Data transmission and reception method and apparatus

Abstract

The application provides a data sending and receiving method and device, relates to the technical field of communication, and is used for solving the problem of multicast service transmission resource waste and improving the frequency spectrum utilization. The method comprises the following steps: a first device sends channel sounding reference signal (SRS) configuration information to at least one terminal device in a first multicast group, the SRS configuration information indicates a first time-frequency resource for sending the SRS, a sequence of the SRS and an antenna port for sending the SRS; the first device receives at least one SRS from the at least one terminal device on the first time-frequency resource, and determines multicast channel state information based on the at least one SRS, wherein the time-frequency resource carrying the at least one SRS is the same, and the sequence of the at least one SRS is the same; the first device determines a physical layer multicast beamforming or a precoding matrix according to the multicast channel state information; and the first device sends multicast data to the at least one terminal device according to the physical layer multicast beamforming or the precoding matrix.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a data transmission and reception method and apparatus. Background Technology

[0002] In the transition from Long Term Evolved (LTE) to New Radio (NR) systems, the link for data transmission between User Equipment (UE) and the base station is called the uplink (the link through which the UE sends information to the base station) or the downlink (the link through which the base station sends information to the UE). The link for data transmission between UEs is called the sidelink (SL). Sidelinks are typically used in vehicle-to-everything (V2X) scenarios or direct communication scenarios such as device-to-device (D2D). Based on the requirement of different user equipment to access the same data content, the downlink and sidelink can support not only unicast but also multicast and broadcast.

[0003] Currently, beamforming or precoding techniques can be used to generate directional beams by adjusting the phase, amplitude, and power of the transmitted signal. This can expand signal coverage, improve edge throughput, and suppress interference, effectively improving system spectral efficiency and addressing resource waste. Base stations need to acquire Channel State Information (CSI) to perform beamforming or precoding on the downlink.

[0004] Specifically, the UE can send a Sounding Reference Signal (SRS). The base station can obtain the channel state information between the UE and the base station by measuring and estimating the signal, taking advantage of channel heterogeneity. Furthermore, the base station can send a Reference Signal (RS) for Channel State Information (CSI) to the UE. The UE obtains the CSI by measuring CSI-RS and then sends a CSI report to the base station, allowing the base station to obtain the channel state information between the UE and the base station based on the CSI report.

[0005] However, for the physical layer of electronic devices, transmitting the same service data through different time-frequency resources leads to a waste of air interface resources. Alternatively, the transmitting device can transmit the same service data using Space Division Multiple Access (SDMA), but the signal transmission power is allocated to different UEs, and there is mutual interference between the transmitted signals of different UEs, resulting in inefficient utilization of signal transmission power. Therefore, it is necessary to research more efficient physical layer multicast technologies to solve the problem of wasted transmission resources in multicast services. Summary of the Invention

[0006] This application provides a data transmission and reception method and apparatus, which can reduce the waste of transmission resources in multicast services and effectively improve spectrum utilization.

[0007] In a first aspect, a data transmission and reception method is provided. This method can be executed by a first device or by a chip applied in the first device; the following example only uses the first device as the executing entity. The method includes: the first device transmitting Channel Sounding Reference Signal (SRS) configuration information to at least one terminal device in a first multicast group. The SRS configuration information indicates a first time-frequency resource for transmitting the SRS, a sequence of the SRS, and an antenna port for transmitting the SRS; the first device receiving at least one SRS from at least one terminal device on the first time-frequency resource, and determining multicast channel state information based on the at least one SRS, wherein the time-frequency resources carrying the at least one SRS are identical, and the sequence of the at least one SRS is identical; the first device determining a physical layer multicast beamforming or precoding matrix based on the multicast channel state information; and the first device transmitting multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0008] In the above technical solution, for a multicast communication scenario between a transmitting device (first device) and multiple receiving devices, the first device can configure SRS configuration information (e.g., multicast-specific SRS configuration information) for at least one terminal device. At least one terminal device within the multicast group can send the same sequence of SRS to the first device on the same time-frequency resources. This at least one SRS on the same time-frequency resources can be considered as a single integrated SRS for the transmitting device, enabling effective measurement of the multicast channel and obtaining its channel state information. Therefore, the first device can determine the physical layer multicast beamforming or precoding matrix based on the multicast channel's channel state information to send multicast data to at least one terminal device in the first multicast group. This improves the utilization rate of spectrum resources in physical layer multicast transmission and minimizes the waste of transmission resources in multicast services.

[0009] In one implementation, at least one SRS is transmitted through the same antenna port.

[0010] In the above possible implementations, multiple terminal devices send SRS to the first device from their respective identical antenna ports. At least one SRS is used by the first device to measure and estimate the multicast channel between the first device and multiple receiving devices. Thus, at least one SRS sent from the same time-frequency resources and the same port can improve the effectiveness and accuracy of multicast channel measurement.

[0011] In one embodiment, the method further includes: a first device receiving at least one antenna port indication information from at least one terminal device, the antenna port indication information indicating the number of antenna ports of the corresponding terminal device, or a set of antenna port indices of the corresponding terminal device; the first device determining an antenna port for transmitting SRS based on the at least one antenna port indication information.

[0012] In the above possible implementations, at least one terminal device reports its own antenna port indication information to the first device, such as the number of antenna ports supported by each terminal device or a set of antenna port indices. Thus, the first device can determine the antenna port used to transmit SRS based on the antenna port indication information of multiple terminal devices, so that each terminal device uses the same antenna port to transmit SRS, thereby improving the accuracy and flexibility of multicast channel measurement.

[0013] In one embodiment, the method further includes: a first device sending first control information to at least one terminal device according to physical layer multicast beamforming or precoding matrix, the first control information being used to indicate time-frequency resources of multicast data, wherein the first control information further includes a group identifier of a first multicast group.

[0014] In the above possible implementations, after the first device determines the physical layer multicast beamforming or precoding matrix, it can multicast first control information to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. For example, the first control information can specifically be SCI or DCI, used to notify at least one terminal device of the time-frequency resources for transmitting multicast data, thereby improving the beam coverage of the first control information and the effectiveness of communication. In addition, the first device does not need to send the first control information to at least one terminal device separately, which can effectively save signaling overhead, conserve communication resources, and improve the efficiency of the communication system.

[0015] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0016] In the above possible implementations, the first device can perform multicast channel measurement on the multicast channel bandwidth through at least one received SRS, and sending multicast data can occupy part or all of the measured multicast channel bandwidth, thereby improving the effectiveness of multicast channel measurement utilization, improving the efficiency of multicast data transmission, and thus improving the data transmission performance of the communication system.

[0017] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0018] In the above possible implementations, when the first device is a network device, the scheme is applicable to downlink multicast channel measurement and downlink multicast data transmission; when the first device is a terminal device on the transmitting side in the first multicast group, the scheme is also applicable to sidelink multicast channel measurement and sidelink multicast data transmission. The technical solution is more universal and flexible, improves the data transmission efficiency of multicast communication, and thus enhances the data transmission performance of the communication system.

[0019] In one implementation, the first device sends an SRS configuration information to at least one terminal device, or the first device sends corresponding SRS configuration information to each of the at least one terminal device, wherein the SRS configuration information corresponding to each terminal device is the same.

[0020] In the above possible implementations, after the first multicast group is formed, the first device can send group-specific SRS configuration information corresponding to the first multicast group to at least one terminal device via a single signaling message, thereby effectively saving communication signaling. If, before the first multicast group is formed, the first device sends the same SRS configuration information to each of the at least one terminal device, the flexibility and feasibility of the SRS configuration information are improved.

[0021] Secondly, a method for obtaining multicast channel state information is provided. This method can be executed by a first terminal device or by a chip applied in the first terminal device. The following example uses the first terminal device as the executing entity. The method includes: the first terminal device receiving channel sounding reference signal (SRS) configuration information from the first device, the SRS configuration information indicating a first time-frequency resource for transmitting the SRS, a sequence of SRS, and an antenna port for transmitting the SRS; the first terminal device transmitting a first SRS on the first time-frequency resource, the first terminal device belonging to a first multicast group, the first time-frequency resource carrying at least one SRS from at least one terminal device in the first multicast group, and the first SRS belonging to at least one SRS, the at least one SRS being used by the first device to determine multicast channel state information; and the first terminal device receiving multicast data from the first device.

[0022] In one implementation, at least one SRS is transmitted through the same antenna port.

[0023] In one embodiment, the method further includes: a first terminal device sending antenna port indication information to a first device, the antenna port indication information indicating the number of antenna ports of the first terminal device, or a set of antenna port indices of the first terminal device; the antenna port indication information is used by the first device to determine the antenna port used to transmit SRS.

[0024] In one embodiment, the method further includes: a first terminal device receiving first control information from a first device, the first control information being used to indicate time-frequency resources for multicast data, wherein the first control information further includes a group identifier of a first multicast group, and the first control information is sent by the first device according to physical layer multicast beamforming or precoding matrix.

[0025] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0026] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0027] Thirdly, a method for acquiring multicast channel state information is provided. This method can be executed by a first device or by a chip applied in the first device; the following example only uses the first device as the executing entity. The method includes: the first device sending at least one first configuration information to at least one terminal device in a first multicast group, the first configuration information indicating the time-frequency resources of the channel state information (CSI) report; the first device sending a channel state information reference signal (CSI-RS) to at least one terminal device; the first device receiving at least one CSI report from at least one terminal device; the first device determining a physical layer multicast beamforming or precoding matrix based on the at least one CSI report; and the first device sending multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0028] In the above technical solution, for a multicast channel between a transmitting device (first device) and multiple receiving devices, the first device can configure first configuration information for at least one terminal device, namely, configuration information for multicast channel-specific CSI reports. Thus, the first device can determine the channel state information of the multicast channel between itself and at least one terminal device based on the CSI reports fed back by different terminal devices on the time-frequency resources indicated by the first configuration information. The first device can then determine a suitable physical layer multicast beamforming or precoding matrix for multicast transmission based on the channel state information, which is used to send multicast data. This improves the utilization rate of spectrum resources in physical layer multicast transmission and minimizes the waste of transmission resources in multicast services.

[0029] In one implementation, the first configuration information includes a first time limit, which is used to instruct at least one terminal device to send a CSI report within the first time limit.

[0030] In the above possible implementations, the first configuration information may include time-domain constraints, i.e., a first time limit, for the terminal device to send CSI reports. This allows the first device to restrict different terminal devices in the multicast group to report CSI reports within a preset time constraint. Within the first time limit, channel state changes can be considered negligible, enabling the first device to determine multicast channel state information more accurately based on the channel state information reflected in multiple CSI reports, thereby effectively improving the utilization rate of the multicast channel.

[0031] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources reported by the Channel State Information (CSI).

[0032] In the above possible implementations, the first device can configure the way the terminal device reports CSI reports to be periodic. Then, the first device can include time-domain constraints on the periodic sending of CSI reports by the terminal device in the first configuration information, namely the sending period and the start time. In this way, the first device can restrict different terminal devices in the multicast group to report CSI reports synchronously at a preset start time and at the same period. This makes the multicast channel status information determined by the first device based on the channel status information reflected by multiple CSI reports more timely and accurate, and effectively improves the utilization rate of the multicast channel.

[0033] In one embodiment, the method further includes: a first device sending a Media Access Control Layer Control Unit (MAC CE) to at least one terminal device, for instructing the at least one terminal device to send a CSI report to the first device.

[0034] In the above possible implementations, the first device can also configure the way the terminal device reports CSI reports to be semi-static, that is, the first device can send a MAC CE to at least one terminal device to instruct the terminal device to send a CSI report to the first device, thereby improving the flexibility of the terminal device reporting CSI reports.

[0035] In one embodiment, the method further includes: a first device sending second control information to at least one terminal device, for instructing at least one terminal device to send a CSI report and immediacy to the first device.

[0036] In the above possible implementations, the way the terminal device reports CSI reports can also be non-periodic, that is, the first device sends second control information to at least one terminal device, such as SCI or DCI. The second control information can be used to instruct the terminal device to send a CSI report to the first device, thereby improving the flexibility and timeliness of the terminal device reporting CSI reports.

[0037] In one embodiment, the method further includes: a first device sending third control information to at least one terminal device according to physical layer multicast beamforming or precoding matrix, the third control information being used to indicate time-frequency resources of multicast data, wherein the third control information further includes a group identifier of a first multicast group.

[0038] In the above possible implementations, after the first device determines the physical layer multicast beamforming or precoding matrix, it can send third control information to at least one terminal device based on the physical layer multicast beamforming or precoding matrix. Specifically, the third control information can be SCI or DCI. The third control information can be used to notify at least one terminal device of the time-frequency resources for transmitting multicast data, thereby improving the beam coverage of the third control information and the effectiveness of communication. Furthermore, the first device does not need to send the third control information separately to at least one terminal device via multicast, which can effectively save signaling overhead, conserve communication resources, and improve the efficiency of the communication system.

[0039] In one implementation, CSI-RS is carried on a first frequency domain resource, and multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0040] In the above possible implementations, the first device can perform multicast channel measurement on the multicast channel bandwidth by sending CSI-RS and receiving at least one CSI report. Sending multicast data can occupy part or all of the measured bandwidth of the multicast channel, thereby obtaining frequency domain diversity gain, improving the efficiency of multicast data transmission, and thus enhancing the data transmission performance of the communication system.

[0041] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0042] In the above possible implementations, when the first device is a network device, the scheme is applicable to downlink multicast channel measurement and downlink multicast data transmission; when the first device is a terminal device on the transmitting side in the first multicast group, the scheme is also applicable to sidelink multicast channel measurement and sidelink multicast data transmission. The technical solution is more universal and flexible, improves the data transmission efficiency of multicast communication, and thus enhances the data transmission performance of the communication system.

[0043] In one embodiment, the first device sends a first configuration information to at least one terminal device, or the first device sends corresponding first configuration information to each of the at least one terminal device, wherein the first configuration information corresponding to each terminal device is the same.

[0044] After the first multicast group is formed, the first device can send the configuration information of the CSI report corresponding to the first multicast group to at least one terminal device through a single signaling message, thereby effectively saving communication signaling. If the first device sends the same CSI report configuration information to each of the at least one terminal device before the first multicast group is formed, the flexibility and feasibility of CSI report resource configuration are improved.

[0045] Fourthly, a method for obtaining multicast channel state information is provided. This method can be executed by a first terminal device or by a chip applied in the first terminal device. The following example only uses the first terminal device as the executing entity. The method includes: the first terminal device receiving first configuration information from the first device, the first configuration information indicating the time-frequency resources for a Channel State Information (CSI) report; the first terminal device receiving a Channel State Information Reference Signal (CSI-RS) from the first device; the first terminal device sending a first CSI report to the first device according to the CSI-RS, the first terminal device belonging to a first multicast group, the time-frequency resources carrying the first CSI report also carrying at least one CSI report from at least one terminal device in the first multicast group, and the first CSI report belonging to the at least one CSI report, the CSI report being used by the first device to determine multicast channel state information; and the first terminal device receiving multicast data from the first device.

[0046] In one implementation, the first configuration information includes a first time limit, which is used to instruct the first terminal device to send a first CSI report within the first time limit.

[0047] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources for which the first terminal device sends the first CSI report.

[0048] In one embodiment, the method further includes: a first terminal device receiving a control unit (MAC CE) from the media access control layer of the first device; and the terminal device sending a first CSI report to the first device based on the MAC CE.

[0049] In one embodiment, the method further includes: a first terminal device receiving second control information from a first device; and the terminal device sending a first CSI report to the first device based on the second control information.

[0050] In one embodiment, the method further includes: a first terminal device receiving third control information from a first device, the third control information being used to indicate time-frequency resources for multicast data, wherein the third control information further includes a group identifier of a first multicast group, and the third control information is sent by the first device according to physical layer multicast beamforming or precoding matrix.

[0051] In one implementation, the first CSI-RS is carried on a first frequency domain resource, and the multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0052] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0053] Fifthly, a communication device is provided, comprising a transmitting module, a receiving module, and a processing module. The transmitting module is configured to transmit Channel Sounding Reference Signal (SRS) configuration information to at least one terminal device in a first multicast group. The SRS configuration information indicates a first time-frequency resource for transmitting the SRS, a sequence of the SRS, and an antenna port for transmitting the SRS. The receiving module is configured to receive at least one SRS from at least one terminal device on the first time-frequency resource and determine multicast channel state information based on the at least one SRS, wherein the time-frequency resources carrying the at least one SRS are identical, and the sequences of the at least one SRS are identical. The processing module is configured to determine a physical layer multicast beamforming or precoding matrix based on the multicast channel state information. The transmitting module is further configured to transmit multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0054] In one implementation, at least one SRS is transmitted through the same antenna port.

[0055] In one embodiment, the receiving module is further configured to receive at least one antenna port indication information from at least one terminal device, the antenna port indication information being used to indicate the number of antenna ports of the corresponding terminal device, or a set of antenna port indices of the corresponding terminal device; the processing module is further configured to determine the antenna port for transmitting SRS based on the at least one antenna port indication information.

[0056] In one embodiment, the sending module is further configured to send first control information to at least one terminal device according to physical layer multicast beamforming or precoding matrix. The first control information is used to indicate the time and frequency resources of multicast data, wherein the first control information also includes the group identifier of the first multicast group.

[0057] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0058] In one embodiment, the communication device is a network device, or it is a terminal device in a first multicast group. Alternatively, it may be a chip or other combination device with the aforementioned network device or terminal device functions applied in a network device or terminal.

[0059] When the communication device is a network device or terminal device, or a combination of devices capable of performing the functions of such network devices or terminal devices, the receiving module can be a receiver, and may include an antenna and radio frequency circuits, etc.; the processing module can be a processor; and the transmitting module can be a transmitter, and may include an antenna and radio frequency circuits, etc., wherein the receiver and transmitter can be an integrated transceiver. When the communication device is a component with the functions of such network devices or terminal devices, the receiving module can be a radio frequency unit, the processing module can be a processor, and the transmitting module can be a radio frequency unit. When the communication device is a chip system applied in a network device or terminal, the receiving module can be the input interface of the chip system, the processing module can be the processor of the chip system, such as a central processing unit (CPU), and the transmitting module can be the output interface of the chip system. The chip system can be a system-on-a-chip (SOC), or a baseband chip, etc., wherein the baseband chip may include a processor, channel encoder, digital signal processor, modem, and interface module, etc.

[0060] In one embodiment, the sending module is further configured to send an SRS configuration information to at least one terminal device, or the sending module is further configured to send corresponding SRS configuration information to each of the at least one terminal device, wherein the SRS configuration information corresponding to each terminal device is the same.

[0061] In a sixth aspect, a communication apparatus is provided, comprising a receiving module and a transmitting module, wherein the receiving module is configured to receive channel sounding reference signal (SRS) configuration information from a first device, the SRS configuration information indicating a first time-frequency resource for transmitting the SRS, a sequence of the SRS, and an antenna port for transmitting the SRS; the transmitting module is configured to transmit the SRS to the first device on the first time-frequency resource, the SRS being used by the first device to determine multicast channel state information of a first multicast group based on at least one SRS; the receiving module is further configured to receive multicast data from the first device.

[0062] In one implementation, the SRS is transmitted via a preset antenna port, or the SRS is transmitted via an antenna port indicated in the SRS configuration information.

[0063] In one embodiment, the transmitting module is further configured to transmit antenna port indication information to the first device, the antenna port indication information indicating the number of antenna ports of the communication device, or a set of antenna port indices of the communication device; the antenna port indication information is used by the first device to determine the antenna port used for transmitting SRS.

[0064] In one embodiment, the receiving module is further configured to receive first control information from the first device. The first control information is used to indicate the time-frequency resources of the multicast data. The first control information also includes a group identifier of the first multicast group. The first control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

[0065] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0066] In one embodiment, the first device is a network device, or the first device is a terminal device in a first multicast group. It can also be a chip or other combination device with the aforementioned network device or terminal device functions applied in a network device or terminal.

[0067] When the communication device is a network device or terminal device, or a combination of devices capable of performing the functions of such network devices or terminal devices, the receiving module can be a receiver, and may include an antenna and radio frequency circuits, etc.; the processing module can be a processor; and the transmitting module can be a transmitter, and may include an antenna and radio frequency circuits, etc., wherein the receiver and transmitter can be an integrated transceiver. When the communication device is a component with the functions of such network devices or terminal devices, the receiving module can be a radio frequency unit, the processing module can be a processor, and the transmitting module can be a radio frequency unit. When the communication device is a chip system applied in a network device or terminal, the receiving module can be the input interface of the chip system, the processing module can be the processor of the chip system, such as a central processing unit (CPU), and the transmitting module can be the output interface of the chip system. The chip system can be a system-on-a-chip (SOC), or a baseband chip, etc., wherein the baseband chip may include a processor, channel encoder, digital signal processor, modem, and interface module, etc.

[0068] A seventh aspect provides a communication apparatus comprising a transmitting module, a receiving module, and a processing module, wherein the transmitting module is configured to transmit at least one first configuration information to at least one terminal device in a first multicast group, the first configuration information being used to indicate the time-frequency resources of a Channel State Information (CSI) report; the transmitting module is further configured to transmit a Channel State Information Reference Signal (CSI-RS) to at least one terminal device; the receiving module is configured to receive at least one CSI report from at least one terminal device; the processing module is configured to determine a physical layer multicast beamforming or precoding matrix based on at least one CSI report; and the transmitting module is further configured to transmit multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0069] In one implementation, the first configuration information includes a first time limit, which is used to instruct at least one terminal device to send a CSI report within the first time limit.

[0070] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources reported by the Channel State Information (CSI).

[0071] In one embodiment, the sending module is further configured to send a Media Access Control Layer Control Unit (MAC CE) to at least one terminal device, instructing the at least one terminal device to send a CSI report to the communication device.

[0072] In one embodiment, the sending module is further configured to send second control information to at least one terminal device, instructing the at least one terminal device to send a CSI report to the communication device.

[0073] In one embodiment, the sending module is further configured to send third control information to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. The third control information is used to indicate the time and frequency resources of the multicast data, wherein the third control information also includes the group identifier of the first multicast group.

[0074] In one implementation, CSI-RS is carried on a first frequency domain resource, and multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0075] In one embodiment, the communication device is a network device, or the communication device is a terminal device in a first multicast group.

[0076] In one embodiment, the sending module is configured to send a first configuration information to at least one terminal device, or the sending module is configured to send corresponding first configuration information to each of the at least one terminal device, wherein the first configuration information corresponding to each terminal device is the same.

[0077] Eighthly, a communication apparatus is provided, comprising a receiving module, a processing module, and a transmitting module, wherein the receiving module is configured to receive first configuration information from a first device, the first configuration information being used to indicate time-frequency resources for a Channel State Information (CSI) report; the receiving module is further configured to receive a Channel State Information Reference Signal (CSI-RS) from the first device; the processing module is configured to transmit a CSI report to the first device based on the CSI-RS, the CSI report being used by the first device to determine multicast channel state information for a first multicast group based on at least one CSI report; and the receiving module is further configured to receive multicast data from the first device.

[0078] In one implementation, the first configuration information includes a first time limit, which instructs the communication device to send a CSI report within the first time limit.

[0079] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources for which the communication device sends CSI reports.

[0080] In one embodiment, the receiving module is further configured to receive a control unit (MAC CE) from the media access control layer of the first device; the sending module is further configured to send a CSI report to the first device based on the MAC CE.

[0081] In one embodiment, the receiving module is further configured to receive second control information from the first device; the sending module is further configured to send a CSI report to the first device using the second control information.

[0082] In one embodiment, the receiving module is further configured to receive third control information from the first device. The third control information is used to indicate the time-frequency resources of the multicast data. The third control information also includes the group identifier of the first multicast group. The third control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

[0083] In one implementation, CSI-RS is carried on a first frequency domain resource, and multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0084] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0085] A ninth aspect provides a communication device comprising a processor and a communication interface; the communication interface being configured to communicate with a module outside the communication device, and the processor being configured to execute a computer program or instructions to implement the method as described in any one of the first aspects above, or to implement the method as described in any one of the third aspects above.

[0086] In a tenth aspect, a communication device is provided, comprising: a processor and a communication interface; the communication interface being configured to communicate with a module outside the communication device, and the processor being configured to execute a computer program or instructions to implement the method as described in any one of the second aspects above, or to implement the method as described in any one of the fourth aspects above.

[0087] Eleventhly, a computer-readable storage medium is provided, characterized in that the computer-readable storage medium includes computer program instructions, which, when executed on a communication device, cause the communication device to perform the method as described in any one of the first aspects above, or the communication device to perform the method as described in any one of the third aspects above.

[0088] In a twelfth aspect, a computer-readable storage medium is provided, characterized in that the computer-readable storage medium includes a computer program that, when run on a computer, causes the computer to perform the method as described in any one of the second aspects above, or the computer to perform the method as described in any one of the fourth aspects above.

[0089] In a thirteenth aspect, a computer program product is provided that, when the computer program product is run on a communication device, causes the communication device to perform the method as described in any one of the first or third aspects above.

[0090] Fourteenth aspect: A computer program product is provided that, when the computer program product is run on a communication device, causes the communication device to perform the method as described in any one of the second or fourth aspects above.

[0091] In a fifteenth aspect, a communication system is provided, the communication system comprising the communication apparatus as described in the fifth aspect above, and the communication apparatus as described in the sixth aspect of the claims.

[0092] In a sixteenth aspect, a communication system is provided, the communication system comprising the communication apparatus as described in the seventh aspect above, and the communication apparatus as described in the eighth aspect of the claims.

[0093] It is understood that any of the communication devices, computer-readable storage media, computer program products and communication systems provided above can be implemented by the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here. Attached Figure Description

[0094] Figure 1 A system architecture diagram of a communication system provided in this application embodiment;

[0095] Figure 2 A system architecture diagram of a communication device provided in this application embodiment;

[0096] Figures 3-7 A flowchart illustrating a method for obtaining multicast channel state information provided in this application embodiment. Figures 1 to 5 ;

[0097] Figure 8 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0098] Figure 9 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0099] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0100] The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to define a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0101] In the following description, specific details such as particular system architectures, interfaces, and technologies are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known mobile devices, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0102] Furthermore, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. First, to facilitate understanding of this application, a brief introduction to the communication technologies and network architecture involved in the embodiments of this application will be provided.

[0103] The technical solutions provided in this application can be used in any communication system that supports sidelink communication. This communication system can be a 3rd generation partnership project (3GPP) communication system, such as a long term evolution (LTE) system; it can also be a 5th generation (5G) mobile communication system, a new radio (NR) system, a vehicle-to-everything (V2X) system, and other next-generation communication systems; it can also be a non-3GPP communication system, without limitation. The following examples illustrate this. Figure 1 Taking an example, the method provided in the embodiments of this application will be described.

[0104] like Figure 1 A schematic diagram illustrating the implementation environment of a communication system provided in an embodiment of this application is shown. Figure 1As shown in the embodiments of this application, a communication system is provided. This communication system may include at least two terminal devices, which are in a multicast group. For example, the first multicast group may include UE1 and UE2. Furthermore, the communication system may also include at least one network device that can send multicast data to the at least two terminal devices. Alternatively, the communication system may also include a single terminal device that can also send multicast data to at least two terminal devices, UE1 and UE2, for example... Figure 1 As shown, the communication system may also include the vehicle UE3.

[0105] In NR systems, there are two types of air interfaces: the Uu interface and the PC5 interface. The Uu interface can be used for communication between terminal devices and network devices, while the PC5 interface can be used for SL communication between terminal devices. In this embodiment, the term "wireless communication" can also be simply referred to as "communication," and the term "communication" can also be described as "data transmission," "information transmission," or "transmission."

[0106] like Figure 1 As shown, the data communication link from the terminal device to the network device is called the uplink (UL), and the data communication link from the network device to the terminal device is called the downlink (DL). The network device can send multicast data to at least two terminal devices UE1 and UE2 through the Uu port. Terminal device UE3 can send multicast data to at least two terminal devices UE1 and UE2 through the PC5 port. UE3 can act as the sending terminal device in the multicast group, and UE1 and UE2 can act as the receiving terminal devices in the multicast group.

[0107] When UE1 and UE2 send the same service request to the same source (such as a network device or a terminal device such as UE3), the source sends the service data to its physical layer according to the service request. The source then sends the same service data to UE1 and UE2 through the physical layer. This same service data can be called physical layer multicast data.

[0108] In this application, the network device can be any device with wireless transceiver capabilities. This includes, but is not limited to: evolved base stations (NodeB, eNB, or e-NodeB) in Long Term Evolution (LTE) systems, base stations (gNodeB or gNB) or transmission receiving points (TRPs) in NR systems, base stations in subsequent 3GPP evolutions, access nodes, wireless relay nodes, and wireless backhaul nodes in WiFi systems. Base stations can be: macro base stations, micro base stations, pico base stations, small cells, relay stations, or balloon stations, etc. Multiple base stations can support networks using the same technology mentioned above, or they can support networks using different technologies mentioned above. A base station can contain one or more co-located or non-co-located TRPs. The network device can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radio access network (CRAN) scenario. The network device can also be a server, wearable device, or vehicle-mounted device, etc. The following explanation uses network devices as base stations as an example. These multiple network devices can be base stations of the same type or different types. A base station can communicate with a terminal device, or it can communicate with a terminal device through a relay station. A terminal device can communicate with multiple base stations using different technologies. For example, a terminal device can communicate with a base station supporting LTE networks, or it can communicate with a base station supporting 5G networks, and it can also support dual connectivity with both LTE and 5G network base stations.

[0109] A terminal device is a device with wireless transceiver capabilities that can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; it can also be deployed on water (such as on ships); and it can be deployed in the air (e.g., on airplanes, balloons, and satellites). The terminal device can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, virtual reality (VR) terminal device, augmented reality (AR) terminal device, wireless terminal in industrial control, vehicle-mounted terminal device, wireless terminal in self-driving, wireless terminal in remote medical care, wireless terminal in smart grids, wireless terminal in transportation safety, wireless terminal in smart cities, wireless terminal in smart homes, wearable terminal devices, etc. The embodiments in this application do not limit the application scenarios. Terminal equipment may also be referred to as User Equipment (UE), Access Terminal Equipment, Vehicle-mounted Terminal, Industrial Control Terminal, UE Unit, UE Station, Mobile Station, Mobile Station, Remote Station, Remote Terminal Equipment, Mobile Equipment, UE Terminal Equipment, Terminal Equipment, Wireless Communication Equipment, UE Agent, or UE Device, etc. Terminal equipment can be fixed or mobile.

[0110] It should be noted that, Figure 1 The accompanying drawings are for illustrative purposes only. Figure 1 The number of devices included is unlimited, and except Figure 1 In addition to the devices shown, this communication architecture can also include other devices. Furthermore, Figure 1 The names of the various devices in the text are not restricted, except... Figure 1 In addition to the names shown, each device may be named with other names without restriction.

[0111] In practical implementation, Figure 1 The network elements shown, such as terminal equipment and network equipment, can be adopted. Figure 2 The shown composition or includes Figure 2 The components shown. Figure 2 This is a schematic diagram of the structure of a communication device 200 provided in an embodiment of this application. When the communication device 200 has the functions of the terminal device described in the embodiment of this application, the communication device 200 can be a terminal device or a chip or system-on-a-chip in the terminal device. When the communication device 200 has the functions of the network device described in the embodiment of this application, the communication device 200 can be a network device or a chip or system-on-a-chip in the network device.

[0112] like Figure 2 As shown, the communication device 200 may include a processor 201, a communication line 202, and a communication interface 203. Furthermore, the communication device 200 may also include a memory 204. The processor 201, memory 204, and communication interface 203 can be connected via the communication line 202.

[0113] The processor 201 can be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device, or any combination thereof. The processor 201 can also be other devices with processing capabilities, such as circuits, devices, or software modules.

[0114] Communication line 202 is used to transmit information between the components included in communication device 200.

[0115] Communication interface 203 is used to communicate with other devices or other communication networks. These other communication networks can be Ethernet, Radio Access Network (RAN), Wireless Local Area Networks (WLAN), etc. Communication interface 203 can be an interface circuit, pins, RF module, transceiver, or any device capable of enabling communication.

[0116] Memory 204 is used to store instructions. These instructions can be computer programs.

[0117] The memory 204 can be a read-only memory (ROM) or other type of static storage device that can store static information and / or instructions; it can also be a random access memory (RAM) or other type of dynamic storage device that can store information and / or instructions; it can also be an electrically erasable programmable read-only memory (EEPROM), a compact optical disc (CD-ROM) or other optical disc storage, optical disk storage, magnetic disk storage medium or other magnetic storage device; optical disk storage includes compressed optical discs, laser discs, optical discs, digital universal optical discs, or Blu-ray discs, etc.

[0118] It should be noted that the memory 204 can exist independently of the processor 201, or it can be integrated with the processor 201. The memory 204 can be used to store instructions, program code, or some data, etc. The memory 204 can be located inside or outside the communication device 200, without limitation. The processor 201 is used to execute the instructions stored in the memory 204 to implement the methods provided in the following embodiments of this application.

[0119] In one example, processor 201 may include one or more CPUs, for example Figure 2 CPU0 and CPU1 in the CPU.

[0120] As an optional implementation, the communication device 200 includes multiple processors, for example, besides Figure 2 In addition to processor 201, it may also include processor 207.

[0121] As an optional implementation, the communication device 200 also includes an output device 205 and an input device 206. For example, the input device 206 is a device such as a keyboard, mouse, microphone, or joystick, and the output device 205 is a device such as a display screen or speaker.

[0122] It should be noted that the communication device 200 can be a wearable device, desktop computer, laptop computer, network server, mobile phone, tablet computer, wireless terminal, embedded device, chip system, or other device. Figure 2 Equipment with a similar structure. Furthermore... Figure 2 The structural composition shown does not constitute a limitation on the communication device, except... Figure 2 In addition to the components shown, the communication device may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0123] In this embodiment of the application, the chip system may be composed of chips or may include chips and other discrete devices.

[0124] For example, the aforementioned device 200 can be a chip system, which can be as follows: Figure 2 As shown, it may include at least one or more processors and transceiver circuits, and the program instructions relating to the methods described in the embodiments of this application are executed in the one or more processors so that the chip system implements the methods of this application.

[0125] Furthermore, the actions, terms, etc., involved in the various embodiments of this application can be referenced interchangeably without limitation. The message names or parameter names in the messages exchanged between the various devices in the embodiments of this application are merely examples, and other names may be used in specific implementations without limitation.

[0126] Next, with Figure 1 Taking the communication system shown as an example, and referring to the corresponding accompanying drawings, the implementation methods provided in this application are described. The devices in the following embodiments may have... Figure 2 The components shown are not intended to limit the scope of this application. Actions, terminology, etc., involved in the various embodiments can be referenced interchangeably without limitation. The message names or parameter names in the messages used for interaction between devices in the embodiments of this application are merely examples; other names may be used in specific implementations without limitation.

[0127] This application provides a method for sending and receiving data. This method can be applied between a first device and at least one terminal device. The first device can be a network device or a terminal device. Specifically, as shown... Figure 3 As shown, the method may include:

[0128] 301: The first device sends SRS configuration information to at least one terminal device in the first multicast group. The SRS configuration information indicates the first time-frequency resource for transmitting SRS, the sequence of SRS, and the antenna port for transmitting SRS.

[0129] Accordingly, the at least one terminal device receives SRS configuration information from the first device.

[0130] For example, the first device may be configured with a group-specific SRS configuration, which is an SRS configuration for determining the multicast channel state. Specifically, the SRS configuration information sent by the first device to at least one terminal device in the first multicast group may be the same. That is, the first device configures group-specific SRS configuration information for the terminal devices in the first multicast group. The time-frequency resources for transmitting SRS, the SRS sequence, and the antenna port corresponding to transmitting SRS indicated in the group-specific SRS configuration information are all the same.

[0131] It should be understood that the multicast channel described in this application can be used by a transmitting device to transmit multicast data to at least one receiving device in the same multicast group. That is, the physical layer channel through which a transmitting device transmits multicast-specific data to at least one receiving device can be called a multicast channel. For example, if a transmitting device scrambles multicast data with a multicast identifier and transmits the multicast data on a multicast channel, terminal devices within the multicast group can receive the multicast data on the same time-frequency resources without interfering with each other. Furthermore, when at least one terminal device within a multicast group is configured to transmit at least one SRS to the transmitting device on the same time-frequency resources, this at least one SRS can be considered by the transmitting device as an integrated SRS on the multicast channel, and the transmitting device determines the channel state of the multicast channel based on this integrated SRS.

[0132] Therefore, the SRS configuration information in this embodiment can specifically be configuration information corresponding to group-specific SRS, used to instruct at least one terminal device in the multicast group to send SRS configuration information. Specifically, the configuration information of group-specific SRS may include time-domain configuration parameters, frequency-domain configuration parameters, port configuration parameters, and SRS sequence configuration parameters.

[0133] For example, the time-domain configuration parameters and frequency-domain configuration parameters included in the SRS configuration information can be used to indicate the first time-frequency resource, that is, to indicate that group-specific SRS sent by at least one terminal device in the first multicast group can be carried on the first time-frequency resource.

[0134] In addition, the SRS configuration information may also include an antenna port for transmitting SRS, meaning that at least one terminal device in the first multicast group can transmit the group-specific SRS through the antenna port indicated in the SRS configuration information.

[0135] Furthermore, the SRS configuration information may also include a sequence for instructing at least one terminal device to send SRS.

[0136] In one implementation, the SRS configuration information may include an initial sequence to instruct at least one terminal device in the corresponding first multicast group to generate a sequence at the time-frequency resource location for transmitting the reference signal. Since the first device configures the same initial sequence for at least one terminal device in the first multicast group, the SRS sequences transmitted by at least one terminal device in the first multicast group are identical in the subsequent step 302.

[0137] It should be noted that, in this embodiment, before the first multicast group is formed, the base station or other network devices can configure a corresponding Radio Network Temporary Identity (RNTI) for each terminal device in the first multicast group. This RNTI is unique and used to identify the terminal device in the communication system. For example, UE1 corresponds to RNTI1, and UE2 corresponds to RNTI2. After the first multicast group is formed, the base station or other network devices can configure a corresponding group identifier for each terminal device in the first multicast group to identify the first multicast group in the communication system. For example, UE1 corresponds to Group1, and UE2 also corresponds to Group1.

[0138] For example, the group identifier can specifically be a Group RNTI, that is, the RNTI is used to distinguish different multicast groups. The Group RNTI can be represented by X bits. This application does not specifically limit this in its embodiments.

[0139] In one implementation, the first device may send an SRS configuration message to at least one terminal device.

[0140] Specifically, when the first device is a network device, the SRS configuration information can be carried in a Radio Resource Control (RRC) message. That is, the network device can add a group-specific SRS configuration information indication field to the RRC message. The network device can send the RRC message to at least one terminal device through the downlink multicast channel to indicate the SRS configuration information corresponding to the first multicast group.

[0141] Furthermore, when the first device is a terminal device, specifically the terminal device (referred to as the transmitting UE) used to send multicast data in the first multicast group, the SRS configuration information can be carried in the PC5 RRC message. That is, the transmitting UE can add a group-specific SRS configuration information indication field to the PC5 RRC message. The transmitting UE can send this PC5 RRC message to at least one terminal device via a side-channel multicast to indicate the SRS configuration information corresponding to the first multicast group.

[0142] The above implementation method is applicable after the first multicast group is grouped. The first device can send the group-specific SRS configuration information corresponding to the first multicast group to at least one terminal device through a single signaling, thereby effectively saving communication signaling.

[0143] Alternatively, in another implementation, the first device may send corresponding SRS configuration information to each of the at least one terminal device.

[0144] Specifically, when the first device is a network device, the network device can send a corresponding RRC message to each of the at least one terminal device. For example, the network device sends RRC1 to UE1, which includes SRS configuration information; the network device sends RRC2 to UE2, which also includes SRS configuration information. The SRS configuration information for each terminal device, such as UE1 and UE2, is identical.

[0145] Furthermore, when the first device is a terminal device, specifically the terminal device (referred to as the transmitting UE) used to send multicast data in the first multicast group, the transmitting UE can send a corresponding PC5 RRC message to each of the at least one terminal device. For example, the transmitting UE sends PC5 RRC1 to the receiving UE1, which includes SRS configuration information; the transmitting UE sends PC5 RRC2 to the receiving UE2, which also includes SRS configuration information. The SRS configuration information is identical for each receiving terminal device.

[0146] The above implementation method applies before the first multicast group is formed. The first device can send the group-specific SRS configuration information corresponding to the first multicast group to N terminal devices through N signaling, where N can be a positive integer greater than 1.

[0147] 302: Each terminal device in the first multicast group sends an SRS to the first device on the first time-frequency resource.

[0148] After at least one terminal device in the first multicast group successfully receives group-specific SRS configuration information from the first device, the at least one terminal device can send an SRS to the first device on the same time-frequency resource (first time-frequency resource) according to the SRS configuration information. Accordingly, the first device receives at least one SRS from the at least one terminal device.

[0149] Specifically, at least one terminal device can send SRS to the first device on the first time-frequency resource indicated in the SRS configuration information.

[0150] Optionally, at least one terminal device uses the same port to transmit SRS, that is, at least one terminal device uses the same number of antenna ports and the corresponding antenna port numbers to send SRS to the first device.

[0151] In one implementation, the terminal device can determine the number of antenna ports for transmitting SRS based on a pre-agreed threshold, or determine the antenna port number for transmitting SRS based on the parameters of a certain antenna port.

[0152] For example, according to the protocol, the threshold for the number of ports through which a terminal device can send group-specific SRS is 2. Therefore, the terminal device can send SRS through ports 1 and 2. Alternatively, according to the protocol, the port index for sending group-specific SRS by the terminal device is nrofSRS-Ports. Based on the index nrofSRS-Ports, it can be determined that the port corresponding to this index is port 1. Therefore, the terminal device can send SRS through port 1.

[0153] In another implementation, the terminal device may report antenna port indication information to the first device in advance. The antenna port indication information may be used to indicate the number of antenna ports of the corresponding terminal device, or the antenna port indication information may be used to indicate the set of antenna port indices of the corresponding terminal device.

[0154] Optionally, the terminal device reports antenna port indication information to the first device. Specifically, before step 301, the first device can determine the antenna port used to transmit SRS based on at least one antenna port indication information reported by at least one terminal device, thereby determining the SRS configuration information.

[0155] In one possible approach, UE1 and UE2 can each report their respective antenna port indication information to the network device, which includes the number of antenna ports. Specifically, this number of antenna ports can be the maximum number of antenna ports that UE1 or UE2 can support. Therefore, the network device can determine the number of antenna ports used for transmitting SRS in the Group Specific SRS configuration information based on the antenna port numbers reported by UE1 and UE2.

[0156] For example, when UE1 reports the number of antenna ports to the network device as A1 and UE2 reports the number of antenna ports to the network device as A2, the number of antenna ports for the SRS in the Group Specific SRS configuration information determined by the network device can be the minimum value between A1 and A2, i.e., min(A1, A2). For example, if A1 > A2, then the number of antenna ports for the SRS can be A2.

[0157] In another possible approach, UE1 and UE2 each report their respective antenna port indication information to the network device. This antenna port indication information includes the maximum set of antenna ports that UE1 or UE2 can support. Therefore, the network device can determine the antenna port set of the SRS in the Group Specific SRS configuration information based on the antenna port sets reported by UE1 and UE2 respectively.

[0158] For example, the maximum set of antenna ports reported by UE1 to the network device is S1, which may include one or more antenna ports supported by UE1; the maximum set of antenna ports reported by UE2 to the network device is S2, which may include one or more antenna ports supported by UE2. The set of antenna ports for the SRS in the Group Specific SRS configuration information determined by the network device is the intersection S of S1 and S2. The set of antenna ports S may include one or more antenna ports supported by both UE1 and UE2.

[0159] 303: The first device determines the multicast channel status information based on at least one SRS.

[0160] Among them, the time-frequency resources carrying at least one SRS are the same, and the sequences of at least one SRS are the same.

[0161] It should be noted that, in the embodiments of this application, if it is assumed that the communication transmission is without delay, the first device can receive at least one SRS from at least one terminal device on the first time-frequency resource. However, in actual applications, the communication transmission has a certain delay. Therefore, there is a certain deviation between the time domain resource for at least one terminal device to send SRS and the time domain resource for the first device to receive SRS. This embodiment of the application ignores this, but it does not mean that there is no delay in actual transmission.

[0162] Specifically, the first device can perform channel measurement and estimation based on at least one SRS according to channel reciprocity to obtain multicast channel state information between the first device and the terminal device. In one possible case, uplink and downlink in a communication system can transmit in different time domains with the same frequency domain resources. Therefore, within a relatively short period of time (the coherence time of channel propagation), it can be assumed that the channel fading experienced by the transmitted signals of the uplink and downlink is the same, i.e., channel reciprocity.

[0163] In this embodiment, the multicast channel state information refers to the channel state information of a multicast channel between a transmitting device (which may be a network device or a terminal device) and multiple receiving devices. The multicast channel is used by the transmitting device to transmit multicast data to multiple receiving devices. The multicast channel state information is specific to the multicast channel and is distinct from the existing channel state information between a transmitting device and a receiving device.

[0164] Specifically, the algorithm by which the first device determines the multicast channel state information based on at least one SRS can be implemented with reference to relevant technologies, and will not be elaborated upon in this application.

[0165] In the above embodiments of this application, the first device can perform channel measurement and estimation based on the SRS sent by multiple terminal devices. Therefore, the signal power of the SRS is higher, which is beneficial to the accuracy of the first device in multicast channel measurement and improves communication quality.

[0166] 304: The first device determines the physical layer multicast beamforming or precoding matrix based on the multicast channel state information.

[0167] In steps 303 and 304 above, the steps performed by the first device can be completed in the same step. For example, the first device can determine the physical layer multicast beamforming or precoding matrix based on at least one SRS. Alternatively, the first device can perform the steps sequentially. For example, the first device can first perform step 303 to obtain multicast channel state information, and then perform step 304 to obtain the physical layer multicast beamforming or precoding matrix. This application does not impose any limitations on this.

[0168] Among them, beamforming technology is a signal preprocessing technology based on antenna arrays, also known as beamforming or spatial filtering technology. It is a signal processing technology that uses sensor arrays to send and receive signals in a directional manner.

[0169] Specifically, in the embodiments of this application, beamforming technology is applied to the data transmitting end. That is, the transmitting end can adjust the parameters of the basic unit of the phase array of the transmitting antenna so that the transmitted signal at certain angles obtains constructive interference, while the transmitted signal at other angles obtains destructive interference, thereby generating a directional transmitted beam that is sent to a specific user and obtains significant array gain.

[0170] In embodiments of this application, a beamforming set can be defined, which may include multiple beamforming or spatial filtering coefficient matrices or vectors. Specifically, different beams in the beamforming set, and the corresponding coefficient matrices or vectors, can be distinguished by index values.

[0171] Furthermore, precoding techniques can preprocess the signal to be transmitted at baseband to generate a precoding matrix. Specifically, the transmitter can allocate limited transmit power to data streams that can be effectively transmitted, based on the number of parallel transmission streams supported by the channel. This allows the transmitted signal to be sent more specifically to particular users, avoiding wasted transmit power.

[0172] Specifically, the algorithm by which the first device determines the multicast beamforming or precoding matrix based on the multicast channel state information can be implemented with reference to relevant technologies, and this application does not impose any specific limitations on it.

[0173] 305: The first device sends multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0174] In one possible implementation, multicast data may be carried on a second time-frequency resource, which has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0175] In other words, the frequency domain resources for sending multicast data can be in the same location as the frequency domain resources for sending SRS. Alternatively, the frequency domain resources for sending multicast data can be a subset of the frequency domain resources for sending SRS.

[0176] For example, the first device is Figure 1 The network device shown in the diagram uses physical layer multicast beamforming or a precoding matrix to send multicast data to UE1 and UE2. The frequency domain resources for transmitting the multicast data are located within the downlink bandwidth part (BWP) of UE1 and also within the downlink BWP of UE2.

[0177] In the above embodiments of this application, the first device can perform multicast channel measurement on the multicast channel bandwidth by sending SRS, and sending multicast data can occupy part or all of the measured multicast channel bandwidth, thereby improving the effectiveness of multicast channel reciprocity utilization, improving the efficiency of multicast data transmission, and thus improving the data transmission performance of the communication system.

[0178] It should be noted that if a transmitting device corresponds to two multicast groups (a set of receiving devices), such as the first device, which corresponds to the first multicast group and the second multicast group. For example, the first multicast group includes UE1 and UE2, and the second multicast group includes UE3 and UE4. The first device can use a physical layer multicast beam or a precoding matrix to send first multicast data to UE1 and UE2 within the first multicast group. The first device can use another physical layer multicast beam or another precoding matrix to send second multicast data to UE3 and UE4 within the second multicast group.

[0179] In one embodiment, the implementation method of this application may further include: a first device may send first control information to at least one terminal device, the first control information being used to indicate the location of time-frequency resources for transmitting multicast data.

[0180] Optionally, the first device sending the first control information to at least one terminal device may occur before step 305 in the aforementioned embodiment, for instructing at least one terminal device on the time-frequency resources for the first device to send multicast data. Thus, after step 305, at least one terminal device can receive multicast data from the first device at the time-frequency resource location indicated by the at least one terminal device.

[0181] In one possible approach, the first device can send first control information to at least one terminal device based on the physical layer multicast beamforming or precoding matrix. That is, the first device sends first control information to at least one terminal device using the physical layer multicast beamforming or precoding matrix determined in step 304 above.

[0182] In the above possible implementations, after the first device determines the physical layer multicast beamforming or precoding matrix, it can multicast first control information to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. For example, the first control information can specifically be SCI or DCI, used to notify at least one terminal device of the time-frequency resources for transmitting multicast data, thereby improving the beam coverage of the first control information and the effectiveness of communication. In addition, the first device does not need to send the first control information to at least one terminal device separately, which can effectively save signaling overhead, conserve communication resources, and improve the efficiency of the communication system.

[0183] Alternatively, in one possible approach, the first device may send first control information to at least one terminal device, instructing the terminal devices on how to receive or decode multicast data. For example, the first device may send the first control information to UE1, and the second device may also send the first control information to UE2. UE1 and UE2 correspond to the same third control information.

[0184] Next, this application will describe in detail the implementation methods of this application in different cases, where the first device is a network device or a terminal device.

[0185] (1) When the first device is a network device:

[0186] Specifically, the first control information can be downlink control information (DCI).

[0187] In one implementation, the network device can send DCI to at least one terminal device based on physical layer multicast beamforming or a precoding matrix. For example, such as... Figure 1 As shown, the network device sends DCI to UE1 and UE2 through a physical layer multicast beam.

[0188] In one possible scenario, the DCI transmitted via multicast can be carried on the Physical Downlink Control Channel (PDCCH).

[0189] Furthermore, the DCI of the multicast transmission may include the Group ID of the first multicast group.

[0190] Specifically, network devices can explicitly indicate the group identifier in the DCI. For example, the network device can add a group identifier indication field to the DCI, such as using the Y bit in the DCI to indicate the group identifier, where Y can be a natural number. Alternatively, the network device can also indicate the group identifier implicitly, that is, by scrambling the multicast transmitted DCI with a Group RNTI. Therefore, only the receiving device corresponding to the Group RNTI can successfully decode the DCI and obtain the data within it.

[0191] In addition, the DCI of a multicast transmission may also include an indicator field for a modulation and coding scheme (MCS), indicating a multicast transmission MCS.

[0192] In another implementation, the network device may also send a DCI to at least one terminal device to instruct the terminal device how to receive or decode multicast data. Then, step 305 is performed, whereby the network device can send multicast data to at least one terminal device according to physical layer multicast beamforming or precoding matrix, wherein the multicast data can be carried on a Physical Downlink Shared Channel (PDSCH).

[0193] For example, such as Figure 1 As shown, the network device sends a DCI to UE1, instructing UE1 on how to receive or decode the PDSCH; in addition, the network device sends a DCI to UE2, instructing UE2 on how to receive or decode the PDSCH.

[0194] Furthermore, the DCI sent by the network device to at least one terminal device may also include the Group ID of the first multicast group. Specifically, the network device may indicate the group ID in the DCI in an explicit or implicit manner, as described above; the specific indication method will not be elaborated here.

[0195] In addition, the DCI sent by the network device to at least one terminal device may also include the MCS.

[0196] Furthermore, in step 305 of the embodiments of this application, the network device can send downlink multicast data to at least one terminal device, such as UE1 and UE2, according to the determined physical layer multicast beamforming or precoding matrix.

[0197] The frequency domain resources for transmitting downlink multicast data by network devices can be located within the downlink BWP of UE1, and also within the downlink BWP of UE2.

[0198] In one possible approach, the frequency domain resource location of the downlink BWP for transmitting downlink multicast data by the network device is the same as the frequency domain resource location of the uplink BWP for transmitting SRS by at least one terminal device. Alternatively, the frequency domain resource location of the downlink BWP for transmitting downlink multicast data by the network device is a subset of the frequency domain resources of the uplink BWP for transmitting SRS by at least one terminal device.

[0199] (2) When the first device is a terminal device:

[0200] The first device is a transmitting-side device in the first multicast that can be used to send multicast data on the side walkway, referred to simply as the transmitting UE. For example, it can be as follows: Figure 1 UE3 is shown.

[0201] At this point, the first control information can specifically be the sidelink control information (SCI).

[0202] In one implementation, the transmitting UE can send SCI to at least one terminal device based on physical layer multicast beamforming or a precoding matrix. For example, such as... Figure 1 As shown, the sending UE, i.e. UE3, can send an SCI to UE1 and UE2 through a physical layer multicast beam, thereby saving energy in signaling transmission.

[0203] Optional, such as Figure 4 As shown, the SCI for this multicast transmission can be carried on the Physical Sidelink Control Channel (PSCCH).

[0204] In another implementation, the transmitting UE may also send an SCI to at least one terminal device to instruct the terminal device how to receive or decode multicast data.

[0205] For example, such as Figure 4 As shown, the transmitting UE can send multicast data to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. The multicast data can be carried on the Physical Sidelink Shared Channel (PSSCH).

[0206] The SCI mentioned above may also include the Group ID of the first multicast group and the MCS indicator. For the specific indicator method, please refer to the relevant description in the preceding embodiments; it will not be repeated here.

[0207] Through the above implementation, the first device can configure group-specific SRS configuration information for multiple terminal devices. At least one terminal device in the multicast group can send the same sequence of SRS to the first device on the same time-frequency resources. This at least one SRS on the same time-frequency resources can be considered as a single integrated SRS by the transmitting device, enabling effective measurement of the multicast channel and obtaining its channel state information. Therefore, the first device can determine the physical layer multicast beamforming or precoding matrix based on the multicast channel's channel state information to send multicast data to at least one terminal device in the first multicast group. This improves the utilization rate of spectrum resources in physical layer multicast transmission and minimizes the waste of transmission resources in multicast services.

[0208] Furthermore, embodiments of this application also provide a method for data transmission and reception, specifically, which can determine multicast channel state information based on feedback information from the channel state of a terminal device. This method can be applied between a first device and at least one terminal device. The first device can be a network device or a terminal device. Specifically, as... Figure 5 As shown, the method may include:

[0209] 501: The first device sends at least one first configuration information to at least one terminal device in the first multicast group, the first configuration information being used to indicate the time and frequency resources reported by the CSI.

[0210] Accordingly, at least one terminal device receives first configuration information from the first device.

[0211] In one implementation, the first configuration information may further include time-frequency resources instructing the first device to transmit CSI-RS. Alternatively, before transmitting the first configuration information to at least one terminal device, the first device may transmit second configuration information to at least one terminal device, the second configuration information being used to instruct the first device to transmit time-frequency resources for CSI-RS.

[0212] It should be noted that the first device can be configured with a Group Specific CSI-RS, i.e., a CSI-RS dedicated to multicast channels. Specifically, it is a reference signal used to indicate the channel state information of a multicast channel between a transmitting device (which can be a network device or a terminal device) and at least one receiving device. The multicast channel can be used by the transmitting device to transmit multicast data to at least one receiving device.

[0213] Therefore, the second configuration information in this embodiment, namely the CSI-RS configuration information, can specifically be the configuration information corresponding to a group-specific CSI-RS, used to instruct the first device to send the time-frequency resource location information of the group-specific CSI-RS to at least one group of terminal devices. Specifically, the configuration information of the group-specific CSI-RS may include time-domain configuration parameters and frequency-domain configuration parameters.

[0214] It should be noted that, in this embodiment, before the first multicast group is formed, the base station or other network device can configure a corresponding RNTI for each terminal device in the first multicast group to uniquely identify the terminal device. For example, UE1 corresponds to RNTI1, and UE2 corresponds to RNTI2. After the first multicast group is formed, the base station or other network device can configure a corresponding group identifier for each terminal device in the first multicast group to identify the first multicast group in the communication system. For example, UE1 corresponds to Group1, and UE2 also corresponds to Group1. Exemplarily, as mentioned above, the group identifier can also be a group RNTI (GroupRNTI).

[0215] In one implementation, the first device may send a first configuration information or a second configuration information to at least one terminal device.

[0216] Specifically, when the first device is a network device, the first configuration information can be carried in an RRC message. That is, the network device can add a group-specific indication field for the first configuration information to the RRC message. The network device can send the RRC message to at least one terminal device through a downlink multicast channel to instruct at least one terminal device in the first multicast group to send the time-domain resource location information of the CSI report.

[0217] Furthermore, when the first device is a terminal device, specifically the terminal device (referred to as the transmitting UE) used to send multicast data in the first multicast group, the first configuration information can be carried in a PC5 RRC message. That is, the transmitting UE can add an indication field for the first configuration information to the PC5 RRC message. The transmitting UE can send this PC5 RRC message to at least one terminal device via a side-channel multicast to indicate the first configuration information corresponding to the first multicast group.

[0218] The above implementation method is applicable after the first multicast group is grouped. The first device can send the time domain resource location information of the CSI report corresponding to the first multicast group to at least one terminal device through a single signaling, thereby effectively saving communication signaling.

[0219] Similarly, the specific implementation of the first device sending the second configuration information to at least one terminal device is similar to that of the first configuration information. For details, please refer to the relevant descriptions above, which will not be repeated here.

[0220] In another implementation, the first device may send corresponding first configuration information or second configuration information to each of the at least one terminal device.

[0221] Specifically, when the first device is a network device, the network device can send a corresponding RRC message to each of the at least one terminal device. For example, the network device sends RRC1 to UE1, which includes SRS configuration information; the network device sends RRC2 to UE2, which includes either first configuration information or second configuration information. The first configuration information and second configuration information are identical for each terminal device.

[0222] Furthermore, when the first device is a terminal device, specifically a terminal device (referred to as the transmitting UE) used to send multicast data in the first multicast group, the transmitting UE can send a corresponding PC5 RRC message to each of the at least one terminal device. For example, the transmitting UE sends PC5 RRC1 to the receiving UE1, which includes either first configuration information or second configuration information. Additionally, the transmitting UE sends PC5 RRC2 to the receiving UE2, which includes either first or second configuration information. The first configuration information and second configuration information are identical for each receiving terminal device, such as UE1 and UE2.

[0223] The above implementation method applies before the first multicast group is formed. The first device can send the group-specific SRS configuration information corresponding to the first multicast group to N terminal devices through N signaling, where N can be a positive integer greater than 1.

[0224] The first device sends corresponding first configuration information to each of the at least one terminal device, and the first configuration information corresponding to each terminal device is the same.

[0225] In one implementation, the first configuration information may include an indication of the frequency domain resource candidate set for which the terminal device sends the CSI report, and time domain constraint information for which the terminal device sends the CSI report. The frequency domain resource candidate set for sending the CSI report may be located at the intersection of the BWPs sent by at least one receiving terminal device within the first multicast.

[0226] Specifically, the first configuration information may include constraint parameters of frequency domain resources. That is, the first configuration information is used to instruct at least one terminal device to send a CSI report to the first device within the bandwidth of the frequency domain resources indicated by the first configuration information.

[0227] The first configuration information can implicitly indicate the time-domain constraints for the terminal device to send CSI reports. For example, the terminal device can send a CSI report to the first device within a duration Z according to the protocol. That is, the maximum value of the time-domain resources for the terminal device to send CSI reports can be less than or equal to the threshold Z.

[0228] In another implementation, the first configuration information may include a first time limit, which is used to instruct at least one terminal device to send a CSI report to the first device within the first time limit.

[0229] Through the above implementation method, the first device can restrict different terminal devices in the multicast group to synchronously report CSI reports within a preset time constraint, so that the multicast channel status information determined by the first device based on the channel status information reflected by multiple CSI reports is more accurate, and the utilization rate of the multicast channel is effectively improved.

[0230] 502: The first device sends CSI-RS to at least one terminal device.

[0231] Specifically, the first device can send CSI-RS to at least one terminal device based on the time-frequency resource location indicated in the aforementioned second configuration information. Correspondingly, at least one terminal device receives CSI-RS from the first device.

[0232] 503: Each terminal device in the first multicast group sends a CSI report to the first device.

[0233] The terminal device receives the CSI-RS from the first device, obtains the CSI by measuring the CSI-RS, and then reports it to the first device via a CSI report. Furthermore, all at least one terminal device performs measurements based on the same multicast CSI-RS and feeds back CSI reports. Correspondingly, the first device receives at least one CSI report from at least one terminal device.

[0234] Among them, at least one terminal device of the receiving end in the first multicast group can synchronously report CSI reports to the first device on the same time and frequency resources according to the instructions of the first configuration information in the aforementioned step 501.

[0235] In one implementation, the terminal device may report CSI reports to the first device periodically, meaning that at least one terminal device sends a CSI report to the first device at regular intervals.

[0236] In this implementation, the first configuration information can be used to indicate the period and start time of the time-frequency resources for CSI reporting. Thus, at least one terminal device can, according to the indication of the first configuration information, send CSI reports to the first device at a certain periodic duration, starting from the start time.

[0237] For example, in the first configuration information, the period of the time-frequency resource for CSI reporting is T, and the start time for sending CSI reports is t1. Then at least one terminal device can simultaneously start at time t1 and report a CSI report to the first device once every T time intervals.

[0238] In the above possible implementations, the first device can configure the way the terminal device reports CSI reports to be periodic. Then, the first device can include time-domain constraints on the periodic sending of CSI reports by the terminal device in the first configuration information, namely the sending period and the start time. In this way, the first device can restrict different terminal devices in the multicast group to report CSI reports synchronously at a preset start time and at the same period. This makes the multicast channel status information determined by the first device based on the channel status information reflected by multiple CSI reports more timely and accurate, and effectively improves the utilization rate of the multicast channel.

[0239] In another implementation, the terminal device can report CSI reports to the first device in a semi-static manner. That is, based on the first device configuring the period and start time of the time-frequency resources for sending CSI reports for at least one terminal device, the terminal device can trigger the reporting of CSI reports to the first device according to the real-time instructions of the first device.

[0240] Specifically, the first device may send a Media Access Control (MAC) control unit (CE) to at least one terminal device to instruct the at least one terminal device to send a CSI report to the first device.

[0241] For example, when the first device is a network device, the network device can configure the same CSI transmission period and the same transmission start time for terminal devices in the group, such as UE1 and UE2, via RRC messages. Furthermore, the network device can also activate a MAC CE to enable the terminal devices in the group to semi-statically report CSI reports to the first device.

[0242] In addition, the terminal device can also report CSI reports to the first device in a non-periodic manner.

[0243] At this time, the first device may also send second control information to at least one terminal device to instruct at least one terminal device to send a CSI report to the first device.

[0244] Specifically, the second control information can be either DCI or SCI. That is, when the first device is a network device, the network device can send DCI to instruct at least one terminal device to report a CSI report; when the first device is a terminal device, the network device can send DCI to instruct at least one terminal device to report a CSI report.

[0245] For example, when the first device is a network device, the network device can trigger at least one terminal device in the multicast group to report a CSI report to the first device on the same time-frequency resource through a multicast DCI.

[0246] In one implementation, the CSI report may include Channel Quality Information (CQI), Rank Indication (RI), Precoding Matrix Indication (PMI), and Layer Indication (LI).

[0247] 504: The first device determines the physical layer multicast beamforming or precoding matrix based on at least one CSI report.

[0248] CSI reports from multiple terminal devices can be used to determine the channel state information of the multicast channel between the transmitting device and multiple receiving devices.

[0249] Specifically, the first device can obtain the channel state information of the multicast channel based on the CSI report received from at least one terminal device, and then determine the physical layer multicast beamforming or precoding matrix based on the obtained multicast channel state information. The specific algorithms involved can be implemented with reference to relevant technologies, and this application does not impose specific limitations on them.

[0250] 505: The first device sends multicast data to at least one terminal device based on the physical layer multicast beamforming or precoding matrix.

[0251] In one implementation, in step 502, the CSI-RS sent by the first device to at least one terminal device can be carried on a first frequency domain resource, and the multicast data can be carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0252] In other words, the frequency domain resources for transmitting multicast data can be in the same location as those for transmitting CSI-RS. Alternatively, the frequency domain resources for transmitting multicast data can be a subset of those for transmitting CSI-RS.

[0253] For example, when the first device is Figure 1 The terminal device UE3 shown can send multicast data to UE1 and UE2 using physical layer multicast beamforming or precoding matrix. The frequency domain resources for transmitting the multicast data can be located within the BWP of UE1 and also within the BWP of UE2.

[0254] In the above embodiments of this application, the first device can perform multicast channel measurement on the multicast channel bandwidth by sending CSI-RS and receiving at least one CSI report. Sending multicast data can occupy part or all of the measured bandwidth of the multicast channel, thereby obtaining frequency domain diversity gain, which improves the effectiveness of multicast channel heterogeneity utilization, improves the efficiency of multicast data transmission, and thus enhances the data transmission performance of the communication system.

[0255] In one embodiment, the implementation method of this application may further include: a first device may send third control information to at least one terminal device, the third control information being used to indicate the location of time-frequency resources for transmitting multicast data.

[0256] The sending of third control information from the first device to at least one terminal device can occur before step 505 in the aforementioned embodiment, and is used to instruct the at least one terminal device on the time-frequency resources for sending multicast data. Therefore, after step 505, the at least one terminal device can receive multicast data from the first device at the time-frequency resource location indicated by the at least one terminal device.

[0257] In one possible approach, the first device can send third control information to at least one terminal device based on the physical layer multicast beamforming or precoding matrix. That is, the first device sends third control information to at least one terminal device using the physical layer multicast beamforming or precoding matrix determined in step 504 above.

[0258] In the above possible implementations, the third control information can specifically be SCI or DCI, used to notify at least one terminal device of the time-frequency resources for transmitting multicast data, thereby improving the beam coverage of the third control information and the effectiveness of communication. Furthermore, the first device does not need to separately multicast the third control information to at least one terminal device, effectively saving signaling overhead, conserving communication resources, and improving the efficiency of the communication system.

[0259] Alternatively, in one possible approach, the first device may send third control information to at least one terminal device, instructing the terminal devices on how to receive or decode multicast data. For example, the first device may send third control information to UE1, and the second device may also send third control information to UE2. UE1 and UE2 use the same third control information.

[0260] Similar to the aforementioned embodiment that determines multicast channel state information based on channel heterogeneity, when the first device is a network device, the third control information can specifically be DCI. When the first device is a terminal device, i.e., the first device is a transmitting device in the first multicast that can be used to send multicast data on the side link, the third control information can specifically be SCI.

[0261] Next, we will introduce each of these in detail.

[0262] (1) When the first device is a network device:

[0263] In one implementation, the network device can send DCI to at least one terminal device based on physical layer multicast beamforming or a precoding matrix. For example, such as... Figure 1 As shown, the network device sends DCI to UE1 and UE2 through a physical layer multicast beam.

[0264] The DCI for this multicast transmission can be carried on the PDCCH. Then, step 505 can be executed, whereby the network device can send multicast data to at least one terminal device based on physical layer multicast beamforming or precoding matrix. Combined with... Figure 6 As shown, multicast data can be carried on the Physical Downlink Shared Channel (PDSCH).

[0265] In another implementation, the network device may also send DCI to at least one terminal device to instruct the terminal device how to receive or decode multicast data.

[0266] For example, such as Figure 1 As shown, the network device sends a DCI to UE1, instructing UE1 on how to receive or decode the PDSCH; in addition, the network device sends a DCI to UE2, instructing UE2 on how to receive or decode the PDSCH.

[0267] Furthermore, the DCI transmitted in the multicast transmission may include the Group ID of the first multicast group. The DCI sent by the network device to at least one terminal device may also include the Group ID of the first multicast group. The group ID indication method described above may include explicit or implicit indication, which will not be elaborated further here.

[0268] In addition, the DCI transmitted via multicast may also include an MCS indication. The DCI sent by a network device to at least one terminal device may also include an MCS.

[0269] Furthermore, in step 505 of the embodiments of this application, the network device may send downlink multicast data to at least one terminal device, such as UE1 and UE2, according to the determined physical layer multicast beamforming or precoding matrix.

[0270] The frequency domain resources for transmitting downlink multicast data by network devices can be located within the downlink BWP of UE1, and also within the downlink BWP of UE2.

[0271] (2) When the first device is a terminal device:

[0272] The first device is a transmitting-side device in the first multicast that can be used to send multicast data on the side walkway, referred to simply as the transmitting UE. For example, it can be as follows: Figure 1 UE3 is shown.

[0273] In one implementation, the transmitting UE can send SCI to at least one terminal device based on physical layer multicast beamforming or a precoding matrix. For example, such as... Figure 1 As shown, the sending UE, i.e. UE3, can send an SCI to UE1 and UE2 through a physical layer multicast beam, thereby saving energy in signaling transmission.

[0274] Among them, such as Figure 7 As shown, the SCI for this multicast transmission can be carried on the PSCCH.

[0275] In another implementation, the transmitting UE may also send an SCI to at least one terminal device to instruct the terminal device how to receive or decode multicast data.

[0276] Then, as Figure 7 As shown, the transmitting UE can send multicast data to at least one terminal device according to the physical layer multicast beamforming or precoding matrix, and the multicast data can be carried on the PSSCH.

[0277] The SCI mentioned above may also include the Group ID of the first multicast group and the MCS indicator. For the specific indicator method, please refer to the relevant description in the foregoing embodiments; it will not be repeated here.

[0278] Through the above implementation method, the first device can configure specific CSI report configuration information for the multicast channel, thereby obtaining channel state information of the multicast channel between a transmitting device and multiple receiving devices based on the CSI reports fed back by different terminal devices. Based on the channel state information of the multicast channel, a suitable physical layer multicast beamforming or precoding matrix for multicast transmission can be determined for transmitting multicast data. This improves the utilization rate of spectrum resources in physical layer multicast transmission and minimizes the waste of transmission resources in multicast services.

[0279] Based on the above-described implementation of the method for determining channel state information based on channel heterogeneity provided in this application, this application provides a communication device for implementing the steps performed by the first device in the above-described implementation. For example... Figure 8 As shown, the communication device 800 may include: a transmitting module 801, a receiving module 802, and a processing module 803.

[0280] The transmitting module 801 can be used to transmit Channel Sounding Reference Signal (SRS) configuration information to at least one terminal device in the first multicast group. The SRS configuration information indicates the first time-frequency resource for transmitting the SRS, the sequence of the SRS, and the antenna port for transmitting the SRS.

[0281] The receiving module 802 can be used to receive at least one SRS from at least one terminal device on a first time-frequency resource, and determine multicast channel state information based on at least one SRS, wherein the time-frequency resources carrying at least one SRS are the same, and the sequences of at least one SRS are the same.

[0282] The processing module 803 can be used to determine the physical layer multicast beamforming or precoding matrix based on the multicast channel state information.

[0283] The sending module 801 can also be used to send multicast data to at least one terminal device according to the physical layer multicast beamforming or precoding matrix.

[0284] In one implementation, at least one SRS is transmitted through the same antenna port.

[0285] In one embodiment, the receiving module 802 is further configured to receive at least one antenna port indication information from at least one terminal device, wherein the antenna port indication information is used to indicate the number of antenna ports of the corresponding terminal device, or a set of antenna port indices of the corresponding terminal device.

[0286] The processing module 803 is also configured to determine the antenna port for transmitting SRS based on at least one antenna port indication information.

[0287] In one embodiment, the sending module 801 is further configured to send first control information to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. The first control information is used to indicate the time and frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group.

[0288] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0289] In one embodiment, the communication device 800 may be a network device, or the communication device 800 may also be a terminal device in the first multicast group.

[0290] In one embodiment, the sending module 801 may also be used to send an SRS configuration information to at least one terminal device, or the sending module 801 may also be used to send the corresponding SRS configuration information to each of the at least one terminal devices, wherein the SRS configuration information corresponding to each terminal device is the same.

[0291] This application also provides a communication device for implementing the steps performed by the terminal device in the above embodiments. For example... Figure 9 As shown, the communication device 900 may include a receiving module 901 and a transmitting module 902.

[0292] The receiving module 901 can be used to receive channel sounding reference signal (SRS) configuration information from the first device. The SRS configuration information indicates the first time-frequency resource for transmitting the SRS, the sequence of the SRS, and the antenna port for transmitting the SRS.

[0293] The sending module 902 can be used to send an SRS to the first device on the first time-frequency resource. The SRS is used by the first device to determine the multicast channel status information of the first multicast group based on at least one SRS.

[0294] The receiving module 901 can also be used to receive multicast data from the first device. The multicast data is sent by the first device according to the physical layer multicast beamforming or precoding matrix, which is determined by the first device according to the multicast channel state information.

[0295] In one implementation, the SRS is transmitted via a preset antenna port, or the SRS is transmitted via an antenna port indicated in the SRS configuration information.

[0296] In one embodiment, the transmitting module 902 can also be used to transmit antenna port indication information to the first device. The antenna port indication information is used to indicate the number of antenna ports of the communication device 900, or a set of antenna port indices of the communication device 900. The antenna port indication information is used by the first device to determine the antenna port used to transmit SRS.

[0297] In one embodiment, the receiving module 901 can also be used to receive first control information from the first device. The first control information is used to indicate the time and frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group. The first control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

[0298] In one implementation, multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

[0299] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0300] Furthermore, based on the implementation method for determining channel state information based on CSI feedback provided in this application, this application also provides a communication device for implementing the steps performed by the first device in the above implementation method. For example... Figure 8 As shown, the communication device 800 may include: a transmitting module 801, a receiving module 802, and a processing module 803.

[0301] The sending module 801 can be used to send at least one first configuration information to at least one terminal device in the first multicast group. The first configuration information is used to indicate the time and frequency resources of the Channel State Information (CSI) report. The sending module 801 can also be used to send a Channel State Information Reference Signal (CSI-RS) to at least one terminal device.

[0302] The receiving module 802 can be used to receive at least one CSI report from at least one terminal device.

[0303] The processing module 803 can be used to determine the physical layer multicast beamforming or precoding matrix based on at least one CSI report.

[0304] The sending module 801 can also be used to send multicast data to at least one terminal device according to the physical layer multicast beamforming or precoding matrix.

[0305] In one implementation, the first configuration information includes a first time limit, which is used to instruct at least one terminal device to send a CSI report within the first time limit.

[0306] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources reported by the Channel State Information (CSI).

[0307] In one embodiment, the sending module 801 can also be used to send a Media Access Control Layer Control Unit (MAC CE) to at least one terminal device, for instructing at least one terminal device to send a CSI report to the communication device.

[0308] In one embodiment, the sending module 801 can also be used to send second control information to at least one terminal device, for instructing at least one terminal device to send a CSI report to the communication device.

[0309] In one embodiment, the sending module 801 can also be used to send third control information to at least one terminal device according to the physical layer multicast beamforming or precoding matrix. The third control information is used to indicate the time and frequency resources of the multicast data. The third control information also includes the group identifier of the first multicast group.

[0310] In one implementation, CSI-RS is carried on a first frequency domain resource, and multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0311] In one embodiment, the communication device 800 may be a network device, or the communication device 800 may also be a terminal device in the first multicast group.

[0312] In one embodiment, the sending module 801 can be used to send a first configuration information to at least one terminal device, or the sending module 801 can be used to send the corresponding first configuration information to each of the at least one terminal device, wherein the first configuration information corresponding to each terminal device is the same.

[0313] This application also provides a communication device for implementing the steps performed by the terminal device in the above embodiments. For example... Figure 8 As shown, the communication device 800 may include: a transmitting module 801, a receiving module 802, and a processing module 803.

[0314] The receiving module 802 can be used to receive first configuration information from the first device, the first configuration information being used to indicate the time and frequency resources of the Channel State Information (CSI) report; the receiving module 802 can also be used to receive the Channel State Information Reference Signal (CSI-RS) from the first device.

[0315] The processing module 803 can be used to send a CSI report to the first device according to the CSI-RS. The CSI report is used by the first device to determine the multicast channel status information of the first multicast group based on at least one CSI report.

[0316] The receiving module 802 can also be used to receive multicast data from the first device. The multicast data is sent by the first device according to the physical layer multicast beamforming or precoding matrix, which is determined by the first device according to the multicast channel state information.

[0317] In one implementation, the first configuration information includes a first time limit, which instructs the communication device to send a CSI report within the first time limit.

[0318] In one implementation, the first configuration information is used to indicate the period and start time of the time-frequency resources for which the communication device sends CSI reports.

[0319] In one embodiment, the receiving module 802 is further configured to receive a control unit MAC CE from the media access control layer of the first device; the sending module 801 is further configured to send a CSI report to the first device based on the MAC CE.

[0320] In one embodiment, the receiving module 802 is further configured to receive second control information from the first device; the sending module 801 is further configured to send a CSI report to the first device using the second control information.

[0321] In one embodiment, the receiving module 802 is further configured to receive third control information from the first device. The third control information is used to indicate the time-frequency resources of the multicast data. The third control information also includes the group identifier of the first multicast group. The third control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

[0322] In one implementation, CSI-RS is carried on a first frequency domain resource, and multicast data is carried on a second frequency domain resource, wherein the second frequency domain resource is the same as the first frequency domain resource, or the second frequency domain resource is a subset of the first frequency domain resource.

[0323] In one implementation, the first device is a network device, or the first device is a terminal device in a first multicast group.

[0324] It should be noted that the specific execution process and embodiments of the above-mentioned communication device can refer to the steps and related descriptions executed by the first device or terminal device in the above-mentioned method embodiments. The technical problems solved and the technical effects brought about can also refer to the content described in the foregoing embodiments, and will not be repeated here.

[0325] In this embodiment, the communication device can be presented in an integrated manner, divided into various functional modules. Here, "module" can refer to a specific circuit, a processor and memory executing one or more software or firmware programs, integrated logic circuits, and / or other devices that can provide the aforementioned functions. In a simple embodiment, those skilled in the art will understand that the communication device can adopt the aforementioned... Figure 2 As shown in the figure.

[0326] For example, Figure 8 The function / implementation process of the processing module 803 can be achieved through... Figure 2 The processor 201 in the memory calls computer program instructions stored in memory 203 to implement the program. For example, Figure 8 The functions / implementation process of the transmitting module 801 and the receiving module 802 can be obtained through Figure 2 It is implemented using the communication interface 204. Figure 9 The functions / implementation process of the receiving module 901 and the transmitting module 902 can be understood through Figure 2 It is implemented using the communication interface 204.

[0327] In some implementations... Figure 2 The processor 201 can call computer execution instructions stored in the memory 203, so that the device 200 can perform the operations performed by the first device or terminal device in the above-described method embodiments, and implement the above-described possible implementation methods of this application.

[0328] The communication group devices in the above-described device embodiments can completely correspond to the first device or terminal device in the method embodiments, with corresponding modules or units performing corresponding steps. For example, when the device is implemented as a chip, the communication unit can be an interface circuit for the chip to receive signals from other chips or devices. The communication unit used for sending or receiving is an interface circuit of the device, used to send signals to other devices. For example, when the device is implemented as a chip, the communication unit can be an interface circuit for sending signals to other chips or devices.

[0329] In an exemplary embodiment, a computer-readable storage medium or a computer program product including instructions is also provided, which can be executed by the processor 201 of the communication device 200 to perform the methods of the above embodiments. Therefore, the technical effects obtained can be referred to the above method embodiments, and will not be repeated here.

[0330] This application also provides a computer program product including instructions that, when executed, enable the computer to perform operations corresponding to those performed by the first device or the terminal device described above.

[0331] This application also provides a system-on-a-chip (SoC) comprising a processing unit and a communication unit. The processing unit may be, for example, a processor, and the communication unit may be, for example, an input / output interface, pins, or circuitry. The processing unit can execute computer instructions to cause the communication device to which the chip is applied to perform the operations performed by the first device or terminal device in the methods provided in this application.

[0332] Optionally, any of the communication devices provided in the above embodiments of this application may include the system chip.

[0333] Optionally, the computer instructions are stored in a storage unit.

[0334] This application also provides a communication system, which may include any of the first devices described in the above embodiments and at least one terminal device.

[0335] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0336] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0337] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A data transmission method, characterized in that, The method includes: The first device sends Channel Sounding Reference Signal (SRS) configuration information to at least one terminal device in the first multicast group. The SRS configuration information indicates a first time-frequency resource for transmitting the SRS, the sequence of the SRS, and an antenna port for transmitting the SRS. The first device receives at least one SRS from the at least one terminal device on the first time-frequency resource, and determines multicast channel state information based on the at least one SRS, wherein the time-frequency resources carrying the at least one SRS are the same, and the sequences of the at least one SRS are the same. The first device determines the physical layer multicast beamforming or precoding matrix based on the multicast channel state information; The first device sends multicast data to the at least one terminal device according to the physical layer multicast beamforming or the precoding matrix.

2. The method according to claim 1, characterized in that, The at least one SRS is transmitted through the same antenna port.

3. The method according to claim 1 or 2, characterized in that, The method further includes: The first device receives at least one antenna port indication information from the at least one terminal device, the antenna port indication information being used to indicate the number of antenna ports of the corresponding terminal device, or a set of antenna port indices of the corresponding terminal device; The first device determines the antenna port for transmitting SRS based on the at least one antenna port indication information.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: The first device sends first control information to the at least one terminal device according to the physical layer multicast beamforming or the precoding matrix. The first control information is used to indicate the time-frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group.

5. The method according to any one of claims 1-4, characterized in that, The multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

6. The method according to any one of claims 1-5, characterized in that, The first device is a network device, or the first device is a terminal device in the first multicast group.

7. The method according to any one of claims 1-6, characterized in that, The first device sends an SRS configuration information to the at least one terminal device, or the first device sends corresponding SRS configuration information to each of the at least one terminal devices, wherein the SRS configuration information corresponding to each terminal device is the same.

8. A data receiving method, characterized in that, The method includes: The first terminal device receives Channel Sounding Reference Signal (SRS) configuration information from the first device, wherein the SRS configuration information indicates the first time-frequency resource for transmitting the SRS, the sequence of the SRS, and the antenna port for transmitting the SRS. The first terminal device sends a first SRS to the first device on the first time-frequency resource. The first terminal device belongs to the first multicast group. The first time-frequency resource carries at least one SRS from at least one terminal device in the first multicast group, and the first SRS belongs to the at least one SRS. The at least one SRS is used by the first device to determine multicast channel state information. The first terminal device receives multicast data from the first device.

9. The method according to claim 8, characterized in that, The at least one SRS is transmitted through the same antenna port.

10. The method according to claim 8 or 9, characterized in that, The method further includes: The first terminal device sends antenna port indication information to the first device. The antenna port indication information is used to indicate the number of antenna ports of the first terminal device, or the set of antenna port indices of the first terminal device; the antenna port indication information is used by the first device to determine the antenna port used to transmit SRS.

11. The method according to any one of claims 8-10, characterized in that, The method further includes: The first terminal device receives first control information from the first device. The first control information is used to indicate the time-frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group. The first control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

12. The method according to any one of claims 8-11, characterized in that, The multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

13. The method according to any one of claims 8-12, characterized in that, The first device is a network device, or the first device is a terminal device in the first multicast group.

14. A communication device, characterized in that, The communication device includes: The transmitting module is configured to transmit Channel Sounding Reference Signal (SRS) configuration information to at least one terminal device in the first multicast group. The SRS configuration information indicates a first time-frequency resource for transmitting the SRS, the sequence of the SRS, and an antenna port for transmitting the SRS. A receiving module is configured to receive at least one SRS from the at least one terminal device on the first time-frequency resource, and determine multicast channel state information based on the at least one SRS, wherein the time-frequency resources carrying the at least one SRS are the same, and the sequences of the at least one SRS are the same. The processing module is used to determine the physical layer multicast beamforming or precoding matrix based on the multicast channel state information. The sending module is further configured to send multicast data to the at least one terminal device according to the physical layer multicast beamforming or the precoding matrix.

15. The apparatus according to claim 14, characterized in that, The at least one SRS is transmitted through the same antenna port.

16. The apparatus according to claim 14 or 15, characterized in that, The receiving module is further configured to receive at least one antenna port indication information from the at least one terminal device, wherein the antenna port indication information is used to indicate the number of antenna ports of the corresponding terminal device, or a set of antenna port indices of the corresponding terminal device; The processing module is further configured to determine the antenna port used for transmitting SRS based on the at least one antenna port indication information.

17. The apparatus according to any one of claims 14-16, characterized in that, The sending module is further configured to send first control information to the at least one terminal device according to the physical layer multicast beamforming or the precoding matrix. The first control information is used to indicate the time-frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group.

18. The apparatus according to any one of claims 14-17, characterized in that, The multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

19. The apparatus according to any one of claims 14-18, characterized in that, The communication device is a network device, or the communication device is a terminal device in the first multicast group.

20. The apparatus according to any one of claims 14-19, characterized in that, The communication device sends an SRS configuration information to the at least one terminal device, or the communication device sends corresponding SRS configuration information to each of the at least one terminal devices, wherein the SRS configuration information corresponding to each terminal device is the same.

21. A communication device, characterized in that, The communication device includes: A receiving module is configured to receive Channel Sounding Reference Signal (SRS) configuration information from a first device, wherein the SRS configuration information indicates a first time-frequency resource for transmitting the SRS, the sequence of the SRS, and an antenna port for transmitting the SRS. The transmitting module is used to transmit a first SRS to the first device on the first time-frequency resource. The communication device belongs to a first multicast group. The first time-frequency resource carries at least one SRS from at least one terminal device in the first multicast group, and the first SRS belongs to the at least one SRS. The at least one SRS is used by the first device to determine multicast channel state information. The receiving module is also used to receive multicast data from the first device.

22. The apparatus according to claim 21, characterized in that, The at least one SRS is transmitted through the same antenna port.

23. The apparatus according to claim 21 or 22, characterized in that, The transmitting module is further configured to transmit antenna port indication information to the first device, the antenna port indication information being used to indicate the number of antenna ports of the communication device, or a set of antenna port indices of the communication device; the antenna port indication information being used by the first device to determine the antenna port used for transmitting SRS.

24. The apparatus according to any one of claims 21-23, characterized in that, The receiving module is further configured to receive first control information from the first device. The first control information is used to indicate the time-frequency resources of the multicast data. The first control information also includes the group identifier of the first multicast group. The first control information is sent by the first device according to the physical layer multicast beamforming or precoding matrix.

25. The apparatus according to any one of claims 21-24, characterized in that, The multicast data is carried on a second time-frequency resource, wherein the second time-frequency resource has the same frequency domain resource as the first time-frequency resource, or the frequency domain resource of the second time-frequency resource is a subset of the frequency domain resource of the first time-frequency resource.

26. The apparatus according to any one of claims 21-25, characterized in that, The first device is a network device, or the first device is a terminal device in the first multicast group.

27. A communication device, characterized in that, The communication device includes: Processor and communication interface; The processor is configured to execute a computer program or instructions stored in the communication device to cause the communication device to perform the method as described in any one of claims 1 to 7.

28. A communication device, characterized in that, The communication device includes: Processor and communication interface; The processor is configured to execute a computer program or instructions stored in the communication device to cause the communication device to perform the method as described in any one of claims 8 to 13.

29. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method according to any one of claims 1 to 7 or 8-13.

30. A communication system, characterized in that, The communication system includes the communication device as described in any one of claims 14-20 and the communication device as described in any one of claims 21-26.

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