Data transmission method, terminal device and network device

Abstract

The embodiment of the application provides a data transmission method, a terminal device and a network device, the method comprises the following steps: a terminal device determines a reporting type of channel state information (CSI), wherein the reporting type is used to represent the relationship between the CSI of a currently reported beam and the CSI of a historically reported beam in a current reporting period; and the terminal device sends the CSI of N beams to a network device according to the reporting type and a codebook parameter, wherein the codebook parameter is used to indicate the number N of the currently reported beams, and N is an integer greater than or equal to 1. The data transmission method, the terminal device and the network device provided by the embodiment of the application can improve the flexibility of CSI reporting, thereby improving the system performance.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201710310753.6, entitled "Data Transmission Method, Terminal Equipment and Network Equipment". Technical Field

[0002] This application relates to the field of communications, and particularly to methods, terminal devices, and network devices for data transmission in the field of communications. Background Technology

[0003] Multiple-input multiple-output (MIMO) technology refers to the use of multiple transmit and receive antennas at both the transmitting and receiving ends, allowing signals to be transmitted and received through these multiple antennas. With the development of multi-antenna technology, Massive MIMO has become an effective means of improving system capacity. In a Massive MIMO system, network devices can be configured with dozens or even hundreds of antennas, enabling simultaneous transmission of different data streams to dozens of users using the same frequency resources, thus significantly improving spectral efficiency.

[0004] Channel state information (CSI) represents the channel attributes of a communication link, and the accuracy of the CSI acquired by network devices largely determines the performance of a Massive MIMO system. Generally, in frequency division duplex (FDD) systems or time division duplex (TDD) systems where channel reciprocity is not well satisfied, terminal devices need to evaluate the CSI, quantize it using a codebook, and report it to the network devices. To achieve high-precision CSI reporting, beam combination reporting technology can be used. Terminal devices can weightedly superimpose multiple codewords to compensate for the accuracy loss of a single codeword.

[0005] When using beam overlay reporting technology, multiple beam position information and their coefficient quantization information need to be reported, resulting in significant overhead. Currently, a typical method to reduce feedback overhead is to use a hierarchical reporting approach for CSI (Cost Per Indication). In beam overlay reporting, the terminal device reports the CSI of multiple beams at T time points, reporting N beams' CSI at each time point. Finally, the CSI of L = T * N beams are aggregated to obtain the final CSI information, where T and N are both positive integers. However, in the existing hierarchical CSI reporting method, which beams' CSI are reported at each of the T time points is pre-configured, and network and terminal devices cannot change the content of the reported CSI. Therefore, improving the flexibility of CSI reporting has become a pressing technical problem. Summary of the Invention

[0006] The data transmission method, terminal device, and network device provided in this application embodiment can improve the flexibility of CSI reporting, thereby improving system performance.

[0007] In a first aspect, a data transmission method is provided, comprising: a terminal device determining a reporting type of Channel State Information (CSI), wherein the reporting type is used to represent the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beams reported in the past within the current reporting period; the terminal device sending the CSI of N beams to a network device according to the reporting type and the codebook parameter, wherein the codebook parameter is used to indicate the number N of the currently reported beams, where N is an integer greater than or equal to 1.

[0008] Specifically, the network device can send a reference signal to the terminal device to measure the channel state. After receiving the reference signal sent by the network device, the terminal device can feed back the CSI of at least one beam to the network device. The network device processes the received CSI of the beam to obtain the measurement result. Optionally, the reference signal can be a channel state information reference signal (CSI-RS), but this embodiment of the application does not limit it to this.

[0009] In this embodiment, before the terminal device reports CSI to the network device, the terminal device and the network device need to determine the reporting type of CSI. This reporting type indicates the relationship between the CSI of the beam currently reported by the terminal device and the CSI of beams reported historically within the current reporting period. Furthermore, the terminal device and the network device can also determine a codebook parameter to indicate the number N of beams currently being reported. This codebook parameter can be pre-agreed or negotiated by the network device and the terminal device before each CSI report; this embodiment does not limit this. Based on the determined CSI reporting type and codebook parameter, the terminal device selects the CSI of N beams and feeds back the CSI of these N beams to the network device. The network device receives the CSI of the N beams fed back by the terminal device and determines the measurement result, i.e., the current channel state of the downlink channel, based on the CSI reporting type.

[0010] The data transmission method of this application embodiment negotiates the CSI reporting type between the terminal device and the network device. The terminal device can send the CSI corresponding to the negotiated reporting type to the network device, which enables the network device or the terminal device to adjust the CSI reported at the current time according to the actual situation to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting and improving system performance.

[0011] In a first possible implementation of the first aspect, the reporting type is any one of the following types: a first type, a second type, and a third type, wherein the first type is used to indicate that the currently reported CSI is the CSI of a new reporting period, the second type is used to indicate that the currently reported CSI is the incremental information of the CSI of the historically reported beam, and the third type is used to indicate that the currently reported CSI is the updated information of the CSI of the historically reported beam.

[0012] Specifically, in this paper, the first, second, and third types mentioned above can be referred to as independent type, enhanced type, and updated type, respectively. The independent type indicates that the terminal device has started reporting a new CSI. If the channel state changes or the network device needs to instruct the terminal device to re-initiate CSI reporting, the reporting type corresponding to the terminal device's current CSI report can be independent type. The enhanced type indicates that the CSI reported by the terminal device at the current moment is incremental information of historically reported CSIs. That is, the terminal device has already reported basic CSI information, and the current report is enhanced CSI information, used to supplement the basic CSI information and improve the accuracy of CSI reporting. The updated type indicates that the terminal device needs to update some historically reported CSIs. If the channel has partially changed, the reporting type corresponding to the terminal device's current CSI report can be updated type.

[0013] Based on the different reporting types mentioned above, the CSI reported by the terminal device can be changed in real time. When the channel remains unchanged, the terminal device can report basic CSI information and, based on this, report enhanced CSI information, while instructing the network device to use the enhanced reporting type, thereby improving the accuracy of CSI reporting. Once the channel changes, the terminal device can trigger a new CSI report or update the CSI of the currently reported beam, while instructing the network device to use the independent or update reporting type, thereby improving the accuracy of CSI reporting.

[0014] In conjunction with the above-described possible implementations of the first aspect, in a second possible implementation of the first aspect, before the terminal device sends the CSI of N beams to the network device according to the reporting type and the codebook parameters, the method further includes: the terminal device determining the codebook parameters; and the terminal device determining the currently reported N beams according to the reporting type and the codebook parameters.

[0015] Specifically, before each CSI report, the terminal device needs to determine which beams to use for CSI reporting at the current time. The terminal device can determine the number of CSIs to be reported at the current time based on the codebook parameters, and then determine the specific beams to be used for reporting CSIs based on the reporting type.

[0016] In conjunction with the above-described possible implementations of the first aspect, in a third possible implementation of the first aspect, the terminal device determines the N beams currently being reported based on the reporting type and the codebook parameters, including: if the reporting type is a first type, the terminal device determines to start a new reporting cycle of CSI reporting and determines the beams corresponding to the N CSIs as the N beams; if the reporting type is a second type, the terminal device determines the beams corresponding to the N CSIs that have not been reported in the current reporting cycle as the N beams; if the reporting type is a third type, the terminal device determines the beams corresponding to the N CSIs that need to be updated among the CSIs that have been reported in the current reporting cycle as the N beams.

[0017] It should be understood that the CSI reporting type mentioned above is agreed upon by the network device and the terminal device before each CSI report by the terminal device. That is, the CSI reporting type determined by the network device and the terminal device must be consistent to ensure that the network device correctly processes the CSI reported by the terminal device. In this embodiment, the network device and the terminal device can determine the CSI reporting type in various ways. Specifically, the reporting type can be determined by the terminal device and notified to the network device, or it can be determined by the network device and notified to the terminal device. This embodiment does not limit this approach.

[0018] In conjunction with the above-described possible implementations of the first aspect, in the fourth possible implementation of the first aspect, the terminal device determines the reporting type of Channel State Information (CSI), including: the terminal device determines the reporting type based on the downlink channel state; the method further includes: the terminal device sends a flag bit indicating the reporting type to the network device based on the reporting type.

[0019] Specifically, the terminal device can determine the reporting type based on the downlink channel status. For example, if the downlink channel changes significantly, the terminal device can determine the reporting type as type one; if the downlink channel remains unchanged, the terminal device can determine the reporting type as type two; and if the downlink channel changes only slightly, the terminal device can determine the reporting type as type three. After determining the reporting type, the terminal device can send the reporting type to the network device. The network device receives the reporting type sent by the terminal device, thereby determining the reporting type of the CSI reported by the terminal device and processing it correctly.

[0020] In one possible implementation, the terminal device can indicate the reporting type of the CSI being reported by sending a flag bit to the network device, and the flag bit has a preset correspondence with the reporting type.

[0021] In conjunction with the above-described possible implementations of the first aspect, in the fifth possible implementation of the first aspect, before the terminal device sends the CSI of N beams to the network device according to the reporting type and codebook parameters, the method further includes: when the reporting type is the first type or the second type, the terminal device receives a flag bit sent by the network device, the flag bit being used to indicate the reporting type; the terminal device determines the reporting type according to the flag bit.

[0022] Specifically, the network device can determine the reporting type based on the CSIs of the beams historically reported by the terminal device in the current reporting cycle. For example, if the network device determines that the historically reported CSIs are useless and a new CSI reporting needs to be started, the network device can determine the reporting type as type one. If the network device determines that the historically reported CSIs are not accurate enough, the network device can determine the reporting type as type two. After determining the reporting type, the network device can send the reporting type to the terminal device. The terminal device receives the reporting type sent by the network device, thereby determining the reporting type of the CSI to be reported by the terminal device this time, and selecting the correct CSI for reporting.

[0023] In one possible implementation, the network device can indicate the reporting type of the CSI being reported by sending a flag bit to the terminal device, and the flag bit has a preset correspondence with the reporting type.

[0024] In conjunction with the above-described possible implementations of the first aspect, in the sixth possible implementation of the first aspect, the terminal device determines the codebook parameters, including: when the reporting type is the first type or the second type, the terminal device receives the codebook parameters sent by the network device.

[0025] In conjunction with the above-described possible implementations of the first aspect, in the seventh possible implementation of the first aspect, after the terminal device determines the codebook parameters, the method further includes: the terminal device sending the codebook parameters to the network device.

[0026] Specifically, when CSI is reported using a codebook method, the terminal device and the network device need to determine not only the reporting type of the current CSI, but also the codebook parameters used for the current CSI reporting. The codebook parameters can be determined by the network device and notified to the terminal device, or the terminal device can determine them and notify the network device; this embodiment does not limit this.

[0027] It should be understood that only when the reporting type is Type 1 or Type 2 can the network device proactively change the content of the CSI report, that is, proactively determine the CSI reporting type and codebook parameters, and send them to the terminal device. However, when the reporting type is update, since the network device cannot know the channel state, only the terminal device can proactively initiate the reporting of Type 3 CSI. In this case, the codebook parameters corresponding to Type 3 can only be determined by the terminal device and notified to the network device.

[0028] In conjunction with the above-described possible implementations of the first aspect, in the eighth possible implementation of the first aspect, the CSI includes at least one of the following information: precoding matrix indicator (PMI), rank indicator (RI), and channel quality indicator (CQI).

[0029] Secondly, another data transmission method is provided, comprising: a network device determining the reporting type of channel state information (CSI) of a terminal device, wherein the reporting type is used to represent the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beams reported in the past within the current reporting period; the network device receiving the CSI of N beams sent by the terminal device, where N is an integer greater than or equal to 1; the network device determining the current channel state of the downlink channel based on codebook parameters, the reporting type, and the CSI of the N beams, wherein the codebook parameters are used to indicate the number N of beams currently reported by the terminal device.

[0030] The data transmission method of this application embodiment negotiates the CSI reporting type between the terminal device and the network device. The terminal device can send the CSI corresponding to the negotiated reporting type to the network device, which enables the network device or the terminal device to adjust the CSI reported at the current time according to the actual situation to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting and improving system performance.

[0031] In a first possible implementation of the second aspect, the reporting type is any one of the following types: a first type, a second type, and a third type, wherein the first type is used to indicate that the currently reported CSI is the CSI of a new reporting period, the second type is used to indicate that the currently reported CSI is the incremental information of the CSI of the historically reported beam, and the third type is used to indicate that the currently reported CSI is the updated information of the CSI of the historically reported beam.

[0032] In conjunction with the above-described possible implementations of the second aspect, in a second possible implementation of the second aspect, the network device determines the current channel state of the downlink channel based on the reporting type, the codebook parameters, and the CSIs of the N beams, including: if the reporting type is a first type, the network device determines that the terminal device starts a new reporting cycle and determines the current channel state based on the CSIs of the N beams; if the reporting type is a second type, the network device aggregates the CSIs of the N beams with the CSIs of the beams already reported in the current reporting cycle to obtain the current channel state; if the reporting type is a third type, the network device updates the CSIs of the N beams already reported in the current reporting cycle to the CSIs of the N beams currently reported by the terminal device and determines the current channel state based on the updated CSIs of the beams.

[0033] In conjunction with the above-described possible implementations of the second aspect, in a third possible implementation of the second aspect, the network device determines the reporting type of the channel state information (CSI) of the terminal device, including: when the reporting type is the first type or the second type, the network device determines the reporting type based on the historically reported CSI of the beam; the method further includes: the network device sends a flag bit indicating the reporting type to the terminal device based on the reporting type.

[0034] In conjunction with the above-mentioned possible implementations of the second aspect, in the fourth possible implementation of the second aspect, the network device determines the reporting type of the Channel State Information (CSI) of the terminal device, including: the network device receiving a flag bit sent by the terminal device, the flag bit being used to indicate the reporting type; and the network device determining the reporting type based on the flag bit.

[0035] In conjunction with the above-described possible implementations of the second aspect, in the fifth possible implementation of the second aspect, before the network device determines the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes: the network device determining the codebook parameters; and, if the reporting type is the first type or the second type, the network device sending the codebook parameters to the terminal device.

[0036] In conjunction with the above-described possible implementations of the second aspect, in the sixth possible implementation of the second aspect, before the network device determines the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes: the network device receiving the codebook parameters sent by the terminal device.

[0037] In conjunction with the above-described possible implementations of the second aspect, in the seventh possible implementation of the second aspect, the CSI includes at least one of the following information: precoding matrix indicator (PMI), rank indicator (RI), and channel quality indicator (CQI).

[0038] Thirdly, a terminal device is provided for executing the method of the first aspect or any possible implementation thereof. Specifically, the terminal device includes a unit for executing the method of the first aspect or any possible implementation thereof.

[0039] Fourthly, a network device is provided for performing the method of the second aspect or any possible implementation thereof. Specifically, the network device includes units for performing the method of the second aspect or any possible implementation thereof.

[0040] Fifthly, a terminal device is provided, comprising: a transceiver, a memory, and a processor. The transceiver, the memory, and the processor communicate with each other via an internal connection path. The memory stores instructions, and the processor executes the instructions stored in the memory to control a receiver to receive signals and to control a transmitter to send signals. When the processor executes the instructions stored in the memory, the execution causes the processor to perform the method of the first aspect or any possible implementation thereof.

[0041] A sixth aspect provides a network device comprising: a transceiver, a memory, and a processor. The transceiver, the memory, and the processor communicate with each other via an internal connection path. The memory stores instructions, and the processor executes the instructions stored in the memory to control a receiver to receive signals and to control a transmitter to transmit signals. When the processor executes the instructions stored in the memory, the execution causes the processor to perform a method of the second aspect or any possible implementation thereof.

[0042] In a seventh aspect, a data transmission system is provided, comprising the terminal device described in the third aspect or any possible implementation thereof, and the network device described in the fourth aspect or any possible implementation thereof; or

[0043] The system includes the terminal device in the fifth aspect or any possible implementation of the fifth aspect and the network device in the sixth aspect or any possible implementation of the sixth aspect.

[0044] Eighthly, a computer program product is provided, the computer program product comprising: computer program code, which, when executed by a network device, causes the network device to perform the method described in the first aspect or any possible implementation thereof.

[0045] Ninthly, a computer program product is provided, the computer program product comprising: computer program code, which, when executed by a terminal device, causes the terminal device to perform the method of the second aspect or any possible implementation thereof.

[0046] In a tenth aspect, a computer-readable medium is provided for storing a computer program including instructions for performing the methods of the first aspect or any possible implementation thereof.

[0047] Eleventhly, a computer-readable medium is provided for storing a computer program including instructions for performing the methods of the second aspect or any possible implementation thereof. Attached Figure Description

[0048] Figure 1 A schematic diagram of a communication system according to an embodiment of this application is shown.

[0049] Figure 2 A schematic flowchart of a data transmission method according to an embodiment of this application is shown.

[0050] Figure 3 A schematic block diagram of a terminal device according to an embodiment of this application is shown.

[0051] Figure 4 A schematic block diagram of a network device according to an embodiment of this application is shown.

[0052] Figure 5 A schematic block diagram of another network device according to an embodiment of this application is shown.

[0053] Figure 6 A schematic block diagram of another terminal device according to an embodiment of this application is shown. Detailed Implementation

[0054] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0055] It should be understood that the technical solutions of the embodiments of this application can be applied to various communication systems, such as: Global System for Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, and future 5G communication systems, etc.

[0056] It should also be understood that the technical solutions of the embodiments of this application can also be applied to various communication systems based on non-orthogonal multiple access technologies, such as sparse code multiple access (SCMA) systems. Of course, SCMA can also be called by other names in the field of communication. Furthermore, the technical solutions of the embodiments of this application can be applied to multi-carrier transmission systems that adopt non-orthogonal multiple access technologies, such as orthogonal frequency division multiplexing (OFDM), filter bank multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), and filtered-OFDM (F-OFDM) systems.

[0057] It should also be understood that, in the embodiments of this application, the terminal device can communicate with one or more core networks via a radio access network (RAN). This terminal device may be referred to as an access terminal, user equipment (UE), user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user apparatus. The access terminal may be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in a future 5G network, or terminal device in a future evolved public land mobile network (PLMN), etc.

[0058] It should also be understood that, in the embodiments of this application, the network device can be used to communicate with the terminal device. The network device can be a base station (BTS) in a GSM or CDMA system, a base station (NB) in a WCDMA system, an evolved Node B (eNB or eNodeB) in an LTE system, or the network device can be a relay station, access point, vehicle-mounted equipment, wearable device, network-side equipment in a future 5G network, or network equipment in a future evolved PLMN network, etc.

[0059] The embodiments of this application can be applied to LTE systems and subsequent evolution systems such as 5G, or other wireless communication systems that use various wireless access technologies, such as systems using code division multiple access, frequency division multiple access, time division multiple access, orthogonal frequency division multiple access, single carrier frequency division multiple access, etc. They are especially suitable for scenarios that require channel information feedback and / or the application of two-level precoding technology, such as wireless networks using Massive MIMO technology, wireless networks using distributed antenna technology, etc.

[0060] It should be understood that Multiple-Input Multiple-Output (MIMO) technology refers to the use of multiple transmit and receive antennas on both the transmitting and receiving devices, enabling signals to be transmitted and received through these antennas, thereby improving communication quality. It makes full use of spatial resources, achieving multiple transmissions and receptions through multiple antennas, and can significantly increase system channel capacity without increasing spectrum resources or antenna transmit power.

[0061] MIMO can be divided into single-user MIMO (SU-MIMO) and multi-user MIMO (MU-MIMO). Massive MIMO is based on the principle of multi-user beamforming. It deploys hundreds of antennas at the transmitting end, modulating the beams of dozens of target receivers. Through spatial signal isolation, it transmits dozens of signals simultaneously on the same frequency resource. Therefore, Massive MIMO technology can fully utilize the spatial freedom brought by large-scale antenna configuration, improving spectral efficiency.

[0062] Figure 1 This is a schematic diagram of the communication system used in the embodiments of this application. For example... Figure 1 As shown, the communication system 100 includes a network device 102, which may include multiple antenna groups. Each antenna group may include one or more antennas. For example, one antenna group may include antennas 104 and 106, another antenna group may include antennas 108 and 110, and an additional group may include antennas 112 and 114. Figure 1 Two antennas are shown for each antenna group; however, more or fewer antennas may be used for each group. Network device 102 may additionally include transmitter chains and receiver chains, which, as will be understood by those skilled in the art, may each include multiple components related to signal transmission and reception, such as processors, modulators, multiplexers, demodulators, demultiplexers, or antennas.

[0063] Network device 102 can communicate with multiple terminal devices, for example, network device 102 can communicate with terminal devices 116 and 122. However, it is understood that network device 102 can communicate with any number of terminal devices similar to terminal devices 116 or 122. Terminal devices 116 and 122 can be, for example, cellular phones, smartphones, laptops, handheld communication devices, handheld computing devices, satellite radio devices, global positioning systems, PDAs, and / or any other suitable devices for communicating on wireless communication system 100.

[0064] like Figure 1As shown, terminal device 116 communicates with antennas 112 and 114, wherein antennas 112 and 114 send information to terminal device 116 via forward link 118 and receive information from terminal device 116 via reverse link 120. Furthermore, terminal device 122 communicates with antennas 104 and 106, wherein antennas 104 and 106 send information to terminal device 122 via forward link 124 and receive information from terminal device 122 via reverse link 126.

[0065] For example, in a frequency division duplex (FDD) system, forward link 118 may utilize a different frequency band than that used by reverse link 120, and forward link 124 may utilize a different frequency band than that used by reverse link 126.

[0066] For example, in time division duplex (TDD) systems and full duplex systems, forward link 118 and reverse link 120 can use a common frequency band, and forward link 124 and reverse link 126 can use a common frequency band.

[0067] Each set of antennas and / or area designed for communication is referred to as a sector of network device 102. For example, antenna sets can be designed to communicate with terminal devices within a sector of the coverage area of ​​network device 102. During communication between network device 102 and terminal devices 116 and 122 via forward links 118 and 124, respectively, the transmitting antennas of network device 102 can utilize beamforming to improve the signal-to-noise ratio of forward links 118 and 124. Furthermore, compared to a network device transmitting signals to all its terminal devices via a single antenna, mobile devices in adjacent cells experience less interference when network device 102 uses beamforming to transmit signals to randomly distributed terminal devices 116 and 122 within the relevant coverage area.

[0068] At any given time, network device 102, terminal device 116, or terminal device 122 may be a wireless communication transmitting device and / or a wireless communication receiving device. When transmitting data, the wireless communication transmitting device may encode the data for transmission. Specifically, the wireless communication transmitting device may acquire a certain number of data bits to be transmitted to the wireless communication receiving device via a channel; for example, the wireless communication transmitting device may generate, receive from other communication devices, or store in memory a certain number of data bits to be transmitted to the wireless communication receiving device via a channel. These data bits may be included in one or more data transport blocks, and the transport blocks may be segmented to generate multiple code blocks.

[0069] Furthermore, the communication system 100 can be a Public Land Mobile Network (PLMN), a device-to-device (D2D) network, a machine-to-machine (M2M) network, or other networks. Figure 1 This is a simplified diagram for ease of understanding only; other network devices may also be included in the network. Figure 1 It was not drawn in the middle.

[0070] Figure 2 A schematic flowchart 200 of a data transmission method according to an embodiment of this application is shown. This method 200 can be applied to... Figure 1 The communication system 100 shown is not limited to this embodiment.

[0071] S210, the terminal device determines the reporting type of channel state information (CSI), wherein the reporting type is used to indicate the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beam reported in the past within the current reporting period.

[0072] S220, the network device determines the reporting type of the Channel State Information (CSI) of the terminal device;

[0073] S230, the terminal device sends N beams of CSI to the network device according to the reporting type and codebook parameters, wherein the codebook parameters are used to indicate the number N of the currently reported beams, and N is an integer greater than or equal to 1;

[0074] Correspondingly, the network device receives the CSI of N beams sent by the terminal device;

[0075] S240, the network device determines the current channel state of the downlink channel based on the reporting type, the codebook parameters, and the CSI of the N beams.

[0076] Codebook-based beamforming relies heavily on Channel State Information (CSI) for codebook selection. In time-varying, slowly varying Time Division Duplex (TDD) systems, network devices can obtain downlink CSI based on uplink channel estimation, leveraging the duality of the channel. However, in Frequency Division Multiplexing (FDD) systems or TDD systems with poor channel reciprocity, due to uplink-downlink channel asymmetry, downlink CSI can only be estimated by the terminal device and then fed back using the uplink channel. Specifically, the network device can send a reference signal to the terminal device to measure the channel state. After receiving the reference signal, the terminal device can feed back the CSI of at least one beam. The network device then processes the received beam CSI to obtain the measurement result.

[0077] As an optional embodiment, the reference signal can be a channel state information reference signal (CSI-RS), but this application embodiment does not limit it to this.

[0078] In this embodiment, before the terminal device reports CSI to the network device, the terminal device and the network device need to determine the reporting type of CSI. This reporting type indicates the relationship between the CSI of the beam currently reported by the terminal device and the CSI of beams reported historically within the current reporting period. Furthermore, the terminal device and the network device can also determine a codebook parameter to indicate the number N of beams currently being reported. This codebook parameter can be pre-agreed or negotiated by the network device and the terminal device before each CSI report; this embodiment does not limit this. Based on the determined CSI reporting type and codebook parameter, the terminal device selects the CSI of N beams and feeds back the CSI of these N beams to the network device. The network device receives the CSI of the N beams fed back by the terminal device and determines the measurement result, i.e., the current channel state of the downlink channel, based on the CSI reporting type.

[0079] In existing CSI hierarchical reporting methods, network devices and terminal devices can pre-configure the beam information to be reported at the next T time points before CSI reporting. That is, within a reporting cycle, multiple CSI reporting times and the beam information to be reported at each time point can be pre-configured for the terminal devices. Since which beams to report at each of the T time points is pre-configured, network devices and terminal devices cannot change the content of the CSI report.

[0080] The data transmission method of this application embodiment negotiates the CSI reporting type between the terminal device and the network device. The terminal device can send the CSI corresponding to the negotiated reporting type to the network device, which enables the network device or the terminal device to adjust the CSI reported at the current time according to the actual situation to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting and improving system performance.

[0081] In one implementation, the high-precision CSI feedback based on beam superposition mechanism uses a codebook to represent the CSI feedback from the terminal device, which can be represented as a two-level codebook structure, typically as follows:

[0082] W = W1 × W2

[0083] Where W1 = [b1 b2 … b K ] represents the basis (beam) selected from the codebook, with a total number of K, and W2 represents the coefficient of the corresponding basis, which can be expressed as:

[0084]

[0085] α ij The coefficients are used to represent amplitude and phase information, i∈{1,…,K}, j∈{1,…,L}, and L is the transmission layer of the user signal.

[0086] The following explanation uses the two-level codebook structure described below as an example.

[0087]

[0088] Among them, b i Used to represent the beam selected by the CSI in the current feedback when using beam stacking mechanism, c j The coefficients mainly include amplitude and phase information, p j This is the amplitude information used to assist in indicating the coefficients.

[0089] It should be understood that the advantage of using a dual-codebook structure is that it can reduce overhead, p j As a long-term broadband parameter, it can remain consistent across the entire uplink bandwidth and can be notified at relatively long intervals, while c j As a subband short-term parameter, it can be notified once in a shorter period on the narrowband, but the embodiments of this application do not limit this.

[0090] Specifically, the terminal device can split the codebook W of the above CSI into two levels of CSI for reporting, as shown below:

[0091]

[0092] CSI information reported based on beams b0 and b1 can be called basic CSI information, while CSI information reported based on beams b2 and b3 can be called enhanced CSI information.

[0093] It should be understood that at least one beam used to report the basic CSI is the beam corresponding to the CSI with the most information among all beams' CSIs. Therefore, the basic CSI includes the main information of the CSI obtained in this measurement. If there is only one beam used to report the basic CSI, then that beam is the optimal beam in the beam selection reporting technique, which will not be elaborated here. The at least one beam used to report the enhanced CSI can be selected by the terminal device from the remaining beams besides the beam used to report the basic CSI. The purpose is to supplement the information of the basic CSI, thereby enabling the network device to obtain a more accurate CSI and significantly improving the CSI feedback quality.

[0094] Therefore, in the hierarchical CSI reporting technology, terminal devices can first report basic CSI, and then report enhanced CSI. As the number of CSIs reported by terminal devices increases, the reporting accuracy of CSI is improved, thereby improving the accuracy of network devices in measuring channel status.

[0095] When using hierarchical CSI reporting, a terminal device can report a portion of the CSI information at different times. For example, the terminal device can report basic CSI information at time T0, first enhanced CSI information at time T0+ΔT, second enhanced CSI information at time T0+2*ΔT, and so on, until all CSI information has been reported. However, since the channel can change at any time, the basic CSI information reported by the terminal device at time T0 is accurate. But if the channel changes between time T0 and time T0+ΔT, the first enhanced CSI information reported by the terminal device at time T0+ΔT will be inaccurate. Thus, continuing to report the first and second enhanced CSI information is meaningless, and the CSI ultimately determined by the network device will not accurately reflect the channel state.

[0096] In existing CSI hierarchical reporting methods, network devices and terminal devices are pre-configured with the beam information to be reported at multiple times in the future, and the network devices and terminal devices cannot change the CSI reporting content at each time. In view of this, embodiments of this application propose the concept of CSI reporting types, so that the CSI reporting content at each time is no longer fixed and can be flexibly changed.

[0097] Considering that during the CSI hierarchical reporting process, channel changes or other situations may occur that require the terminal device to re-report CSI, three CSI reporting types are defined below. However, it should be understood that the CSI reporting type can also be other types, and the embodiments of this application are not limited to these.

[0098] As an optional embodiment, the reporting type is any one of the following types:

[0099] The three types are: a first type, a second type, and a third type. The first type indicates that the currently reported CSI is the CSI of a new reporting period. The second type indicates that the currently reported CSI is the incremental information of the CSI of the historically reported beam. The third type indicates that the currently reported CSI is the updated information of the CSI of the historically reported beam.

[0100] Specifically, the reporting type of CSI can include a first type, a second type, and a third type. For ease of understanding, the first type is referred to as the independent type, the second type as the enhanced type, and the third type as the update type. However, it should be understood that this does not constitute any limitation on the scope of protection of the embodiments of this application. The independent type indicates that the terminal device has started reporting a new CSI. If the channel state changes or the network device needs to instruct the terminal device to re-initiate CSI reporting, the reporting type corresponding to the CSI reported by the terminal device this time can be the independent type. The enhanced type indicates that the CSI reported by the terminal device at the current moment is incremental information of historically reported CSIs; that is, the terminal device has already reported basic CSI information, and the current report is enhanced CSI information, used to supplement the basic CSI information and improve the accuracy of CSI reporting. The update type indicates that the terminal device needs to update some historically reported CSIs. If the channel has partially changed, the reporting type corresponding to the CSI reported by the terminal device this time can be the update type.

[0101] Based on the different reporting types mentioned above, the CSI reported by the terminal device can be changed in real time. When the channel remains unchanged, the terminal device can report basic CSI information and, based on this, report enhanced CSI information, while instructing the network device to use the enhanced reporting type, thereby improving the accuracy of CSI reporting. Once the channel changes, the terminal device can trigger a new CSI report or update the CSI of the currently reported beam, while instructing the network device to use the independent or update reporting type, thereby improving the accuracy of CSI reporting.

[0102] As an optional embodiment, before the terminal device sends the CSI of N beams to the network device according to the reporting type and the codebook parameters, the method further includes:

[0103] The terminal device determines the codebook parameters;

[0104] The terminal device determines the N beams to be reported currently based on the reporting type and the codebook parameters.

[0105] Specifically, before each CSI report, the terminal device needs to determine which beams to use for CSI reporting at the current time. The terminal device can determine the number of CSIs to be reported at the current time based on the codebook parameters, and then determine the specific beams to be used for reporting CSIs based on the reporting type.

[0106] As an optional embodiment, the terminal device determines the N beams currently being reported based on the reporting type and the codebook parameters, including:

[0107] If the reporting type is the first type, the terminal device determines to start a new reporting cycle of CSI reporting, and determines the beams corresponding to the N CSIs as the N beams;

[0108] If the reporting type is the second type, the terminal device will determine the beams corresponding to the N CSIs that have not been reported in the current reporting period as the N beams;

[0109] If the reporting type is the third type, the terminal device determines the beams corresponding to the N CSIs that need to be updated among the CSIs that have been reported in the current reporting cycle as the N beams.

[0110] Correspondingly, the network device determines the current channel state of the downlink channel based on the reporting type, the codebook parameters, and the CSI of the N beams, including:

[0111] If the reporting type is the first type, the network device determines that the terminal device starts a new reporting cycle, and determines the current channel state based on the CSI of the N beams;

[0112] If the reporting type is the second type, the network device aggregates the CSIs of the N beams with the CSIs of the beams that have been reported in the current reporting period to obtain the current channel state;

[0113] If the reporting type is the third type, the network device updates the CSI of the N beams that have been reported in the current reporting period to the CSI of the N beams currently reported by the terminal device, and determines the current channel state based on the updated CSI of the beams.

[0114] For ease of understanding, the first type will be called the independent type, the second type the enhanced type, and the third type the update type. Specifically, the following explanations will address the different reporting types: independent, enhanced, and update.

[0115] (1) Independent type

[0116] If the CSI reporting type is independent, the terminal device determines that a new reporting cycle of CSI reporting needs to be started. First, the terminal device determines the number of N beams of CSI that need to be reported this time according to the codebook parameters. Then, the terminal device determines the beams corresponding to the N CSIs with the largest amount of information as the N beams that need to be reported this time, and sends the CSIs of the N beams to the network device.

[0117] Correspondingly, the network device receives the CSIs of N beams sent by the terminal device. Based on the reporting type of this CSI, the network device determines that the CSIs of N beams reported by the terminal device are of an independent type. The network device then determines that the terminal device has started a new CSI report, identifies the CSIs of these N beams as basic CSI information, and further determines the current channel state.

[0118] (2) Enhancement type

[0119] If the CSI reporting type is enhanced, the terminal device determines the information to be reported for enhanced CSI. First, the terminal device determines the N beams of CSI that need to be reported this time based on the codebook parameters. Then, the terminal device determines the beams corresponding to the N CSIs with the largest amount of information among the CSIs that have not been reported in the current reporting period as the N beams that need to be reported this time, and sends the CSIs of the N beams to the network device.

[0120] Correspondingly, the network device receives the CSIs of N beams sent by the terminal device. Based on the reporting type of the current CSI, the network device determines that the CSIs of N beams reported by the terminal device are of the enhanced type. The network device identifies the CSIs of the N beams as enhanced CSIs and further combines them with the basic CSIs reported by the terminal device in the past to determine the current channel state.

[0121] (3) Update type

[0122] If the CSI reporting type is update type, the terminal device determines that it needs to update some of the CSIs that have been reported in the current reporting period. First, the terminal device determines the N beams of CSIs that need to be reported this time according to the codebook parameters. Then, the terminal device determines the beams corresponding to the N CSIs that need to be updated in the CSIs that have been reported in the current reporting period as the N beams that need to be reported this time, and sends the N beams of CSIs to the network device.

[0123] Correspondingly, the network device receives the CSIs of N beams sent by the terminal device. Based on the reporting type of this CSI, the network device determines that the CSIs of N beams reported by the terminal device this time are of the update type. The network device updates the CSIs of the N beams that have been reported in the current reporting period to the CSIs of the N beams currently reported by the terminal device, and further determines the current channel state.

[0124] It should be understood that the CSI reporting type mentioned above is agreed upon by the network device and the terminal device before each CSI report by the terminal device. That is, the CSI reporting type determined by the network device and the terminal device must be consistent to ensure that the network device correctly processes the CSI reported by the terminal device. In this embodiment, the network device and the terminal device can determine the CSI reporting type in various ways. Specifically, the reporting type can be determined by the terminal device and notified to the network device, or it can be determined by the network device and notified to the terminal device. This embodiment does not limit this approach.

[0125] As an optional embodiment, the terminal device determines the reporting type of Channel State Information (CSI), including:

[0126] The terminal device determines the reporting type based on the downlink channel status;

[0127] The method further includes:

[0128] The terminal device sends a flag bit indicating the reporting type to the network device according to the reporting type.

[0129] Correspondingly, the network device determines the reporting type of Channel State Information (CSI) of the terminal device, including:

[0130] The network device receives a flag bit sent by the terminal device, the flag bit being used to indicate the reporting type;

[0131] The network device determines the reporting type based on the flag bit.

[0132] Specifically, the terminal device can determine the reporting type based on changes in the downlink channel. For example, if the downlink channel changes significantly, the terminal device can determine the reporting type as independent; if the downlink channel remains unchanged, the terminal device can determine the reporting type as enhanced; and if the downlink channel changes only slightly, the terminal device can determine the reporting type as updated. After determining the reporting type, the terminal device can send the reporting type to the network device. The network device receives the reporting type sent by the terminal device, thereby determining the reporting type of the CSI reported by the terminal device and processing it correctly.

[0133] In one possible implementation, the terminal device can indicate the reporting type of the CSI being reported by sending a flag bit to the network device. Specifically, there is a preset correspondence between the flag bit and the reporting type. For example, 00 corresponds to an independent type, 01 corresponds to an enhanced type, 11 corresponds to an update type, and so on. After the terminal device determines that the reporting type is an independent type, it can determine that the flag bit is 00 according to the correspondence between the reporting type and the flag bit, and send 00 to the network device. After receiving the flag bit 00, the network device can determine that the reporting type is an independent type according to the correspondence between the reporting type and the flag bit.

[0134] It should be understood that the above use of 2 bits to represent the flag bit is merely for illustrative purposes. The flag bit in this application embodiment can also be represented by other bits or other characters, and this application embodiment does not limit this.

[0135] As an optional embodiment, the network device determines the reporting type of Channel State Information (CSI) of the terminal device, including:

[0136] When the reporting type is the first type or the second type, the network device determines the reporting type based on the CSI of the historically reported beams;

[0137] After the network device determines the reporting type based on the CSI of the historically reported beams, the method further includes:

[0138] The network device sends a flag bit indicating the reporting type to the terminal device according to the reporting type.

[0139] Correspondingly, before the terminal device sends N beams of CSI to the network device according to the reporting type and codebook parameters, the method further includes:

[0140] The terminal device receives a flag bit sent by the network device, the flag bit being used to indicate the reporting type;

[0141] The terminal device determines the reporting type based on the flag bit.

[0142] Specifically, the network device can determine the reporting type based on the CSIs of the beams historically reported by the terminal device in the current reporting cycle. For example, if the network device determines that the historically reported CSIs are useless and a new CSI reporting needs to be started, the network device can determine that the reporting type is an independent type (i.e., the first type mentioned above). If the network device determines that the historically reported CSIs are not accurate enough, the network device can determine that the reporting type is an enhanced type (i.e., the second type mentioned above). After determining the reporting type, the network device can send the reporting type to the terminal device. The terminal device receives the reporting type sent by the network device, thereby determining the reporting type of the CSI to be reported by the terminal device this time, and selecting the correct CSI for reporting.

[0143] In one possible implementation, the network device can indicate the reporting type of the CSI being reported by sending a flag bit to the terminal device. Specifically, there is a preset correspondence between the flag bit and the reporting type. For example, 00 corresponds to an independent type, 01 corresponds to an enhanced type, 11 corresponds to an update type, and so on. After the network device determines that the reporting type is an independent type, it can determine that the flag bit is 00 according to the correspondence between the reporting type and the flag bit, and send 00 to the terminal device. After receiving the flag bit 00, the terminal device can determine that the reporting type is an independent type according to the correspondence between the reporting type and the flag bit.

[0144] It should be understood that the above use of 2 bits to represent the flag bit is merely for illustrative purposes. The flag bit in this application embodiment can also be represented by other bits or other characters, and this application embodiment does not limit this.

[0145] As an optional embodiment, before the network device determines the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes:

[0146] The network device determines the codebook parameters;

[0147] When the reporting type is the first type or the second type, the network device sends the codebook parameters to the terminal device.

[0148] Correspondingly, before the terminal device sends N beams of CSI to the network device according to the reporting type and codebook parameters, the process includes:

[0149] When the reporting type is the first type or the second type, the terminal device receives the codebook parameters sent by the network device.

[0150] As an optional embodiment, after the terminal device determines the codebook parameters, the method further includes:

[0151] The terminal device sends the codebook parameters to the network device.

[0152] Correspondingly, before the network device determines the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes:

[0153] The network device receives the codebook parameters sent by the terminal device.

[0154] Specifically, when CSI is reported using a codebook method, the terminal device and the network device need to determine not only the reporting type of the current CSI, but also the codebook parameters used for the current CSI reporting. The codebook parameters can be determined by the network device and notified to the terminal device, or the terminal device can determine them and notify the network device; this embodiment does not limit this.

[0155] It should be understood that only when the reporting type is an independent type (i.e., the first type mentioned above) or an enhanced type (i.e., the second type mentioned above) can the network device actively modify the reported content of the CSI, that is, actively determine the reporting type and codebook parameters of the CSI and send them to the terminal device. However, when the reporting type is an update type (i.e., the third type mentioned above), since the network device cannot know the channel state, only the terminal device can actively initiate the reporting of the update type CSI. In this case, the codebook parameters corresponding to the update type can only be determined by the terminal device and notified to the network device.

[0156] As an optional embodiment, the CSI includes at least one of the following: Precoding Matrix Indicator (PMI), Rank Indicator (RI), and Channel Quality Indicator (CQI).

[0157] Specifically, the Channel State Information (CSI) fed back from the terminal device to the network device may include at least one of Rank Indication (RI), Precoding Matrix Indication (PMI), and Channel Quality Indication (CQI). RI identifies the available layer number for spatial transmission at the transmitting end, PMI identifies the codebook index of the optimal precoding matrix, and CQI is the channel quality at the time of RI / PMI reporting, used by the transmitting end to select the modulation scheme and coding rate for transmission.

[0158] It should be understood that the CSI mentioned above may also include other information. For example, in beam superposition reporting technology, the CSI may also include coefficient quantization information. This application embodiment does not limit this.

[0159] For ease of understanding, the data transmission method of this application embodiment will be described in detail below with reference to three possible implementation methods.

[0160] Method 1

[0161] (1) First moment

[0162] The terminal device can select the optimal beam b0 from multiple candidate beams based on beam selection reporting technology and send the CSI of beam b0 to the network device. At this time, the total number of beams reported by the terminal device to represent the measurement result (hereinafter referred to as UE CSI) is L=1.

[0163] Correspondingly, the network device receives the CSI of beam b0 reported by the terminal device, determines the channel state of the current downlink channel based on the CSI of beam b0, and performs data transmission according to the channel state.

[0164] (2) Second moment

[0165] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at this second moment is the enhanced type. The terminal device selects a beam b1 from the remaining candidate beams (excluding b0) and sends the CSI of beam b1 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L = 2.

[0166] Correspondingly, the network device receives the CSI of beam b1 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the second time is the enhanced type based on the received flag bit. The network device aggregates the CSI of beam b1 with the CSI of beam b0 to obtain the channel state of the current downlink channel, and performs data transmission according to the channel state.

[0167] Method 2

[0168] (1) First moment

[0169] The terminal device can select the two beams b0 and b1 corresponding to the CSI with the most information from multiple candidate beams based on beam combination reporting technology, and send the CSI of beams b0 and b1 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L=2.

[0170] Correspondingly, the network device receives the CSI of beams b0 and b1 reported by the terminal device, determines the channel state of the current downlink channel based on the CSI of beams b0 and b1, and performs data transmission based on the channel state.

[0171] (2) Second moment

[0172] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at this second moment is the enhanced type. The terminal device selects two beams, b2 and b3, from the remaining candidate beams other than b0 and b1, and sends the CSI of beams b2 and b3 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L = 4.

[0173] Correspondingly, the network device receives the CSIs of beams b2 and b3 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the second moment is the enhanced type based on the received flag bit. The network device aggregates the CSIs of beams b2 and b3 with the CSIs of beams b0 and b1 to obtain the channel state of the current downlink channel, and performs data transmission according to the channel state.

[0174] (3) Third moment

[0175] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at this third moment is the enhanced type. The terminal device selects two beams, b4 and b5, from the remaining candidate beams other than b0, b1, b2, and b3, and sends the CSI of beams b4 and b5 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L = 6.

[0176] Correspondingly, the network device receives the CSI of beams b4 and b5 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the third moment is the enhanced type based on the received flag bit. The network device aggregates the CSI of beams b4 and b5 with the CSI of beams b0, b1, b2 and b3 to obtain the channel state of the current downlink channel, and performs data transmission according to the channel state.

[0177] In this way, as the terminal devices report more and more CSIs, the network devices can obtain higher-precision CSIs, and the quality of CSI feedback can be significantly improved.

[0178] Method 3

[0179] (1) First moment

[0180] The terminal device can select the two beams b0 and b1 corresponding to the CSI with the most information from multiple candidate beams based on beam combination reporting technology, and send the CSI of beams b0 and b1 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L=2.

[0181] Correspondingly, the network device receives the CSI of beams b0 and b1 reported by the terminal device, determines the channel state of the current downlink channel based on the CSI of beams b0 and b1, and performs data transmission based on the channel state.

[0182] (2) Second moment

[0183] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at this second moment is the enhanced type. The terminal device selects two beams, b2 and b3, from the remaining candidate beams other than b0 and b1, and sends the CSI of beams b2 and b3 to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L = 4.

[0184] Correspondingly, the network device receives the CSIs of beams b2 and b3 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the second moment is the enhanced type based on the received flag bit. The network device aggregates the CSIs of beams b2 and b3 with the CSIs of beams b0 and b1 to obtain the channel state of the current downlink channel, and performs data transmission according to the channel state.

[0185] (3) Third moment

[0186] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at this third moment is an independent type. The terminal device then determines to trigger a new CSI report, remeasures the channel state, selects the six beams b0-b5 corresponding to the CSI with the largest information content from multiple candidate beams, and sends the CSI of beams b0-b5 at the current moment to the network device. At this time, the total number of beams reported by the terminal device to represent the UE CSI is L = 6.

[0187] Correspondingly, the network device receives the CSI of beams b0-b5 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the third moment is independent based on the received flag bit. The network device determines that the terminal device starts a new reporting cycle, determines the channel state of the current downlink channel based on the CSI of beams b0-b5, and performs data transmission based on the channel state.

[0188] (3) Fourth moment

[0189] The terminal device determines the flag bit for the currently reported CSI, which indicates the reporting type of the current CSI. The terminal device sends this flag bit to the network device. Based on this flag bit, the terminal device determines that the reporting type of the CSI at the fourth moment is an update type. The terminal device selects beams b4 and b5 from beams b0-b5 that have been reported in this reporting period but whose CSIs have changed, and sends the CSIs of beams b4 and b5 to the network device. At this time, the total number of beams reported by the UE to represent the UE CSI is L = 6.

[0190] Correspondingly, the network device receives the CSIs of beams b4 and b5 reported by the terminal device, and receives a flag bit sent by the terminal device to indicate the reporting type of the current CSI. The network device determines that the reporting type of the CSI reported by the terminal device at the fourth time is an update type based on the received flag bit. The network device updates the CSIs of beams b4 and b5 reported by the terminal device at the third time, determines the channel state of the current downlink channel based on the updated CSIs of beams b0-b5, and performs data transmission based on the channel state.

[0191] In this embodiment of the application, the CSI reported by the terminal device can be changed in real time. Once the channel changes, the terminal device can trigger a new CSI report or update the CSI of the currently reported beam, thereby improving the accuracy of CSI reporting.

[0192] It should be understood that the above times are all pre-configured CSI reporting times, and the second time is after the first time, the third time is after the second time, and the fourth time is after the third time.

[0193] The data transmission method of this application embodiment, by setting a flag bit to indicate the reporting type of CSI at the current time, enables network devices or terminal devices to adjust the CSI reported at the current time according to the actual situation, so as to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting.

[0194] It should be understood that the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0195] The above text combines Figures 1 to 2 The data transmission method according to the embodiments of this application is described in detail below, in conjunction with... Figures 3 to 6 The present application provides a detailed description of the terminal device and network device according to embodiments thereof.

[0196] Figure 3 This application illustrates a terminal device 300 provided in an embodiment of the present application. The terminal device 300 includes a determining unit 310 and a transceiver unit 320.

[0197] The determining unit 310 is used to determine the reporting type of Channel State Information (CSI). The reporting type is used to indicate the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beam reported in the past within the current reporting period.

[0198] The transceiver unit 320 is used to send the CSI of N beams to the network device according to the reporting type and codebook parameters. The codebook parameters are used to indicate the number N of the currently reported beams, where N is an integer greater than or equal to 1.

[0199] The terminal device in this application embodiment negotiates the CSI reporting type with the network device. The terminal device can send the CSI corresponding to the negotiated reporting type to the network device. This enables the network device or the terminal device to adjust the CSI reported at the current time according to the actual situation to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting and improving system performance.

[0200] Optionally, the reporting type is any one of the following types: a first type, a second type, and a third type, wherein the first type is used to indicate that the currently reported CSI is the CSI of a new reporting period, the second type is used to indicate that the currently reported CSI is the incremental information of the CSI of the historically reported beam, and the third type is used to indicate that the currently reported CSI is the updated information of the CSI of the historically reported beam.

[0201] Optionally, the determining unit 310 is further configured to: determine the codebook parameters before sending the CSI of N beams to the network device according to the reporting type and the codebook parameters; and determine the N beams currently being reported according to the reporting type and the codebook parameters.

[0202] Optionally, the determining unit 310 is specifically used to: if the reporting type is a first type, determine to start a new reporting cycle for CSI reporting, and determine the beams corresponding to the N CSIs as the N beams; if the reporting type is a second type, determine the beams corresponding to the N CSIs that have not been reported in the current reporting cycle as the N beams; if the reporting type is a third type, determine the beams corresponding to the N CSIs that need to be updated among the CSIs that have been reported in the current reporting cycle as the N beams.

[0203] Optionally, the determining unit 310 is specifically used to: determine the reporting type according to the downlink channel state; the transceiver unit 320 is further used to: send a flag bit indicating the reporting type to the network device according to the reporting type.

[0204] Optionally, the transceiver unit 320 is further configured to: receive a flag bit sent by the network device when the reporting type is the first type or the second type, the flag bit being used to indicate the reporting type; the determining unit 310 is specifically configured to: determine the reporting type based on the flag bit.

[0205] Optionally, the transceiver unit 320 is further configured to: before sending the CSI of N beams to the network device according to the reporting type and codebook parameters, if the reporting type is the first type or the second type, receive the codebook parameters sent by the network device.

[0206] Optionally, the transceiver unit 320 is further configured to: send the codebook parameters to the network device after the codebook parameters are determined.

[0207] It should be understood that the terminal device 300 here is embodied in the form of a functional unit. The term "unit" here can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, combined logic circuitry, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the terminal device 300 can specifically be the terminal device in the above embodiments. The terminal device 300 can be used to execute the various processes and / or steps corresponding to the terminal device in the above method embodiments; to avoid repetition, these will not be described again here.

[0208] Figure 4 This application illustrates a network device 400 provided in an embodiment of the present application. The network device 400 includes: a determining unit 410 and a transceiver unit 420.

[0209] The determining unit 410 is used to determine the reporting type of the channel state information (CSI) of the terminal device. The reporting type is used to indicate the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beam reported in the past within the current reporting period.

[0210] The transceiver unit 420 is used to receive the CSI of N beams sent by the terminal device, where N is an integer greater than or equal to 1;

[0211] The determining unit 410 is further configured to:

[0212] The current channel state of the downlink channel is determined based on the codebook parameters, the reporting type, and the CSI of the N beams. The codebook parameters are used to indicate the number N of beams currently reported by the terminal device.

[0213] The network device in this application embodiment negotiates the CSI reporting type with the terminal device. The terminal device can send the CSI corresponding to the negotiated reporting type to the network device. This enables the network device or the terminal device to adjust the CSI reported at the current time according to the actual situation to meet the needs of constantly changing channels, thereby improving the flexibility of CSI reporting and improving system performance.

[0214] Optionally, the reporting type is any one of the following types: a first type, a second type, and a third type, wherein the first type is used to indicate that the currently reported CSI is the CSI of a new reporting period, the second type is used to indicate that the currently reported CSI is the incremental information of the CSI of the historically reported beam, and the third type is used to indicate that the currently reported CSI is the updated information of the CSI of the historically reported beam.

[0215] Optionally, the determining unit 410 is specifically configured to: if the reporting type is a first type, determine that the terminal device starts a new reporting cycle, and determine the current channel state based on the CSIs of the N beams; if the reporting type is a second type, aggregate the CSIs of the N beams with the CSIs of the beams already reported in the current reporting cycle to obtain the current channel state; if the reporting type is a third type, update the CSIs of the N beams already reported in the current reporting cycle to the CSIs of the N beams currently reported by the terminal device, and determine the current channel state based on the updated CSIs of the beams.

[0216] Optionally, the determining unit 410 is specifically configured to: determine the reporting type based on the CSI of the historically reported beam when the reporting type is the first type or the second type; the transceiver unit 420 is further configured to: send a flag bit indicating the reporting type to the terminal device based on the reporting type.

[0217] Optionally, the transceiver unit 420 is further configured to: receive a flag bit sent by the terminal device, the flag bit being used to indicate the reporting type;

[0218] The determining unit 410 is specifically used to: determine the reporting type based on the flag bit.

[0219] Optionally, the determining unit 410 is further configured to: determine the codebook parameters before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams; the transceiver unit 420 is further configured to: send the codebook parameters to the terminal device when the reporting type is the first type or the second type.

[0220] Optionally, the transceiver unit 420 is further configured to: receive the codebook parameters sent by the terminal device before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams.

[0221] It should be understood that the network device 400 here is embodied in the form of a functional unit. The term "unit" here can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, integrated logic circuitry, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the network device 400 can specifically be the network device in the above embodiments, and the network device 400 can be used to execute the various processes and / or steps corresponding to the network device in the above method embodiments; to avoid repetition, these will not be described again here.

[0222] Figure 5 Another network device 500 provided in this application embodiment is illustrated. The network device 500 includes a processor 510, a transceiver 520, and a memory 530. The processor 510, transceiver 520, and memory 530 communicate with each other via an internal connection path. The memory 530 is used to store instructions, and the processor 510 is used to execute the instructions stored in the memory 530 to control the transceiver 520 to transmit and / or receive signals.

[0223] When the program instructions stored in the memory 530 are executed by the processor 510, the processor 510 is used to determine the reporting type of the channel state information (CSI) of the terminal device. The reporting type is used to indicate the relationship between the CSI of the beam currently reported by the terminal device and the CSI of the beams reported in the past within the current reporting period. The processor 510 receives the CSI of N beams sent by the terminal device through the transceiver 520, where N is an integer greater than or equal to 1. The processor 510 is also used to determine the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams. The codebook parameters are used to indicate the number N of beams currently reported by the terminal device.

[0224] The processor 510 and memory 530 described above can be combined into a single processing device. The processor 510 executes the program code stored in the memory 530 to achieve the aforementioned functions. In specific implementations, the memory 530 can be integrated into the processor 510 or independent of the processor 510.

[0225] The network device 500 may further include an antenna 540 for transmitting downlink data or downlink control signaling output by the transceiver 520 via a wireless signal. It should be understood that the network device 500 may specifically be the network device in embodiment 200 above, and may be used to execute the various steps and / or processes corresponding to the network device in method embodiment 200 above. Optionally, the memory 530 may include read-only memory and random access memory, and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information. The processor 510 may be used to execute instructions stored in the memory, and when the processor 510 executes instructions stored in the memory, the processor 510 is used to execute the various steps and / or processes of the method embodiment corresponding to the network device above.

[0226] Figure 6 Another terminal device 600 provided in an embodiment of this application is shown. For example... Figure 6 As shown, the terminal device 600 includes a processor 601 and a transceiver 602. Optionally, the terminal device 600 also includes a memory 603. The processor 602, transceiver 602, and memory 603 communicate with each other via internal connections to transmit control and / or data signals. The memory 603 stores computer programs, and the processor 601 retrieves and runs the computer programs from the memory 603 to control the transceiver 602 to transmit and receive signals.

[0227] When the program instructions stored in memory 603 are executed by processor 601, processor 601 determines the reporting type of channel state information (CSI). The reporting type indicates the relationship between the CSI of the currently reported beam and the CSI of the historically reported beams within the current reporting period. Based on the reporting type and codebook parameters, transceiver 602 sends the CSI of N beams to the network device. The codebook parameters indicate the number N of the currently reported beams, where N is an integer greater than or equal to 1.

[0228] The processor 601 and memory 603 described above can be combined into a single processing device. The processor 601 executes the program code stored in the memory 603 to achieve the aforementioned functions. In specific implementations, the memory 603 can be integrated into the processor 601 or independent of the processor 601. The terminal device 600 described above may also include an antenna 604 for transmitting uplink data or uplink control signaling output by the transceiver 602 via wireless signals.

[0229] It should be understood that the terminal device 600 may specifically be the terminal device in embodiment 200 above, and can be used to execute the various steps and / or processes corresponding to the terminal device in method embodiment 200 above. Optionally, the memory 630 may include read-only memory and random access memory, and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information. The processor 610 can be used to execute instructions stored in the memory, and when the processor 610 executes instructions stored in the memory, the processor 610 is used to execute the various steps and / or processes of the method embodiment corresponding to the terminal device above.

[0230] The processor 601 described above can be used to execute the actions implemented internally by the terminal as described in the preceding method embodiments, while the transceiver 602 can be used to execute the actions of the terminal transmitting or sending data to the terminal device as described in the preceding method embodiments. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0231] The aforementioned terminal device 600 may also include a power supply 606 for providing power to various devices or circuits in the terminal device 600.

[0232] In addition, to further enhance the functionality of the terminal device, the terminal device 600 may also include one or more of an input unit 606, a display unit 607, an audio circuit 608, a camera 609, and a sensor 610, etc. The audio circuit may also include a speaker 6082, a microphone 6084, etc.

[0233] It should be understood that, in the embodiments of this application, the processors of the network device 500 and the terminal device 600 can be central processing units (CPUs), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0234] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware processor, or as a combination of hardware and software units within the processor. The software units can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0235] It should be understood that the term "and / or" in this article 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, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0236] Those skilled in the art will recognize that the method steps and units described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the steps and components of each embodiment have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0237] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0238] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0239] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0240] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0241] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0242] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered 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 by, include: Determine the reporting type of Channel State Information (CSI), wherein the reporting type is used to indicate whether the CSI of the currently reported beam is the CSI of the new reporting period, or the relationship between the CSI of the currently reported beam and the CSI of the historically reported beam. Determine the codebook parameters; the codebook parameters are those sent to the network device. Alternatively, receive the codebook parameters sent by the network device; Based on the reporting type and the codebook parameters, determine the N beams currently being reported, and send the CSI of the N beams to the network device. The codebook parameters are used to indicate the number N of the beams currently being reported, where N is an integer greater than or equal to 1.

2. The method according to claim 1, characterized in that, The reporting type is any one of the following types: The three types are: a first type, a second type, and a third type. The first type indicates that the currently reported CSI is the CSI of a new reporting period; the second type indicates that the currently reported CSI is the incremental information of the CSI of the historically reported beam; and the third type indicates that the currently reported CSI is the updated information of the CSI of the historically reported beam.

3. The method according to claim 1 or 2, characterized in that, Determine the reporting type of Channel State Information (CSI), including: The reporting type is determined based on the downlink channel state; The method further includes: According to the reporting type, a flag bit indicating the reporting type is sent to the network device.

4. The method according to claim 2, characterized in that, Determine the reporting type of Channel State Information (CSI), including: When the reporting type is the first type or the second type, a flag bit sent by the network device is received, the flag bit being used to indicate the reporting type; The reporting type is determined based on the flag bit.

5. The method according to claim 2 or 4, characterized in that, Before sending N beams of CSI to the network device according to the reported type and codebook parameters, the method further includes: When the reporting type is the first type or the second type, the codebook parameters sent by the network device are received.

6. A data transmission method, characterized in that, include: Determine the reporting type of the Channel State Information (CSI) of the terminal device. The reporting type is used to indicate whether the CSI of the beam currently reported by the terminal device in the current reporting period is the CSI of the new reporting period, or the relationship between the CSI of the currently reported beam and the CSI of the beam reported in the past. Receive the CSI of N beams sent by the terminal device, where N is an integer greater than or equal to 1; The current channel state of the downlink channel is determined based on the codebook parameters, the reporting type, and the CSI of the N beams. The codebook parameters are used to indicate the number N of beams currently reported by the terminal device. The method further includes: Receive the codebook parameters sent by the terminal device; Alternatively, the codebook parameters may be sent to the terminal device.

7. The method according to claim 6, characterized in that, The reporting type is any one of the following types: The three types are: a first type, a second type, and a third type. The first type indicates that the currently reported CSI is the CSI of a new reporting period. The second type indicates that the currently reported CSI is the incremental information of the CSI of the historically reported beam. The third type indicates that the currently reported CSI is the updated information of the CSI of the historically reported beam.

8. The method according to claim 7, characterized in that, Determine the reporting type of Channel State Information (CSI) from the terminal device, including: If the reporting type is the first type or the second type, the reporting type is determined based on the CSI of the historically reported beam; The method further includes: According to the reporting type, a flag bit indicating the reporting type is sent to the terminal device.

9. The method according to claim 6 or 7, characterized in that, Determine the reporting type of Channel State Information (CSI) from the terminal device, including: Receive a flag bit sent by the terminal device, the flag bit being used to indicate the reporting type; The reporting type is determined based on the flag bit.

10. The method according to claim 7 or 8, characterized in that, Before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes: Determine the codebook parameters; When the reporting type is the first type or the second type, the codebook parameters are sent to the terminal device.

11. The method according to any one of claims 6 to 8, characterized in that, Before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the method further includes: Receive the codebook parameters sent by the terminal device.

12. A communication device, characterized in that, include: The processing unit is used to determine the reporting type of Channel State Information (CSI), wherein the reporting type is used to indicate whether the CSI of the currently reported beam is the CSI of the new reporting period, or the relationship between the CSI of the currently reported beam and the CSI of the historically reported beam. The processing unit is further configured to determine codebook parameters and, based on the reporting type and the codebook parameters, determine the N beams currently being reported; The transceiver unit is configured to send the CSI of the N beams to the network device according to the reporting type and codebook parameters, wherein the codebook parameters indicate the number N of beams currently being reported, where N is an integer greater than or equal to 1. The transceiver unit is also used to send or receive the codebook parameters.

13. The communication device according to claim 12, characterized in that, The reporting type is any one of the following types: The three types are: a first type, a second type, and a third type. The first type indicates that the currently reported CSI is the CSI of a new reporting period. The second type indicates that the currently reported CSI is the incremental information of the CSI of the historically reported beam. The third type indicates that the currently reported CSI is the updated information of the CSI of the historically reported beam.

14. The communication device according to claim 12 or 13, characterized in that, The processing unit is specifically used for: The reporting type is determined based on the downlink channel state; The transceiver unit is also used for: According to the reporting type, a flag bit indicating the reporting type is sent to the network device.

15. The communication device according to claim 13, characterized in that, The transceiver unit is also used for: When the reporting type is the first type or the second type, a flag bit sent by the network device is received, the flag bit being used to indicate the reporting type; The processing unit is specifically used for: The reporting type is determined based on the flag bit.

16. The communication device according to claim 13 or 15, characterized in that, The transceiver unit is also used for: Before sending the CSI of N beams to the network device according to the reporting type and codebook parameters, if the reporting type is the first type or the second type, the codebook parameters sent by the network device are received.

17. The communication device according to any one of claims 12 to 13 and 15, characterized in that... The processing unit is a processor, and the transceiver unit is a transceiver.

18. A communication device, characterized in that, include: The processing unit is used to determine the reporting type of the Channel State Information (CSI) of the terminal device. The reporting type is used to indicate whether the CSI of the beam currently reported by the terminal device in the current reporting period is the CSI of the new reporting period, or the relationship between the CSI of the currently reported beam and the CSI of the beam reported in the past. The transceiver unit is used to receive the CSI of N beams sent by the terminal device, where N is an integer greater than or equal to 1; The processing unit is also used for: The current channel state of the downlink channel is determined based on the codebook parameters, the reporting type, and the CSI of the N beams. The codebook parameters are used to indicate the number N of beams currently reported by the terminal device. The transceiver unit is also used for: Send or receive the codebook parameters.

19. The communication device according to claim 18, characterized in that, The reporting type is any one of the following types: The three types are: a first type, a second type, and a third type. The first type indicates that the currently reported CSI is the CSI of a new reporting period. The second type indicates that the currently reported CSI is the incremental information of the CSI of the historically reported beam. The third type indicates that the currently reported CSI is the updated information of the CSI of the historically reported beam.

20. The communication device according to claim 19, characterized in that, The processing unit is specifically used for: If the reporting type is the first type or the second type, the reporting type is determined based on the CSI of the historically reported beam; The transceiver unit is also used for: According to the reporting type, a flag bit indicating the reporting type is sent to the terminal device.

21. The communication device according to claim 18 or 19, characterized in that, The transceiver unit is also used for: Receive a flag bit sent by the terminal device, the flag bit being used to indicate the reporting type; The processing unit is specifically used for: The reporting type is determined based on the flag bit.

22. The communication device according to claim 19 or 20, characterized in that, The processing unit is also used for: The codebook parameters are determined before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams. The transceiver unit is also used for: When the reporting type is the first type or the second type, the codebook parameters are sent to the terminal device.

23. The communication device according to claim 20 or 21, characterized in that, The transceiver unit is also used for: Before determining the current channel state of the downlink channel based on the codebook parameters, the reporting type, and the CSI of the N beams, the codebook parameters are sent to the terminal device if the reporting type is of type one or type two.

24. The communication device according to any one of claims 18 to 20, characterized in that, The processing unit is a processor, and the transceiver unit is a transceiver.

25. A computer-readable medium for storing a computer program, characterized in that, When the computer program is executed by a computer, the method as described in any one of claims 1 to 11 is implemented.

26. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a computer, the method as described in any one of claims 1 to 11 is implemented.

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