Channel state information feedback method and related product

Abstract

The invention discloses a channel state information feedback method and a related product. The network equipment sends first indication information; and the terminal equipment sends second indication information according to the first indication information, and the second indication information is used for indicating the X groups of base vectors. The first indication information is used for indicating the P groups of base vectors, the X groups of base vectors belong to the P groups of base vectors, and only the base vectors for representing the feature subspace beams need to be selected from limited base vector groups, so that the base vector indication overhead for representing the feature subspace beams is reduced, and meanwhile, the processing complexity is reduced; or the first indication information is used for indicating K base vectors, K is a positive integer greater than or equal to 1, each group of base vectors in the X groups of base vectors comprises M base vectors, the M base vectors belong to the K base vectors, and M is less than or equal to K. As the network equipment is configured with more base vectors, a certain selection space is provided for the terminal equipment, and the compromise of report overhead and feedback precision can be realized.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a channel state information feedback method and related products. Background Art

[0002] The fifth generation (5 th The 5G generation (5G) mobile communication system has higher requirements for system capacity and spectrum efficiency. In the 5G mobile communication system, the application of large-scale multi-antenna technology plays a vital role in improving the spectrum efficiency of the system. When using multi-input multi-output (MIMO) technology, the base station needs to precode the data before sending it to the terminal device. How to perform precoding depends on the channel state information (CSI) fed back by the terminal device to the base station, so accurate CSI feedback information is an important factor affecting system performance.

[0003] In frequency division duplex (FDD) mode, the frequency band interval of the uplink and downlink channels is much larger than the coherent bandwidth, and the uplink and downlink channels do not have complete reciprocity, requiring the terminal device to feedback the CSI of the downlink channel to the base station. The base station determines the precoding of the data transmitted to the terminal device based on the precoding matrix indicator (PMI) fed back by the terminal device.

[0004] PMI feedback is determined and reported based on a set of codebooks. The design of the FDD CSI codebook is a basic and important issue in 5G mobile communication systems. At present, a codebook based on statistical characteristic subspace is proposed. The codebook is characterized by a linear combination of a set of spatial-frequency domain joint characteristic subspace beams. For this type of codebook, the terminal device needs to feedback the statistical characteristic subspace beam for a long period and the beam superposition coefficient for a short period. If the elements of the long-period feedback statistical characteristic subspace beam are directly fed back, the feedback overhead is large. Therefore, how to reduce the overhead of feedback characteristic subspace beams is a key issue for this type of codebook. Summary of the invention

[0005] The present application provides a channel state information feedback method and related products to reduce the overhead of feedback characteristic subspace beams.

[0006] In a first aspect, a channel state information feedback method is provided, which is executed by a terminal device or a chip or circuit for a terminal device. The method includes: receiving first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and the P and the M are positive integers greater than or equal to 1; and sending second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and the X is a positive integer greater than or equal to 1. With this method, the terminal device only needs to select the basis vectors used to characterize the characteristic subspace beams from a limited group of basis vectors, thereby reducing the basis vector indication overhead used to characterize the characteristic subspace beams, and reducing the processing complexity of the terminal device.

[0007] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: radio resource control (RRC) signaling, medium access control-control element (MAC-CE), and downlink control information (DCI).

[0008] In a possible implementation, the first indication information includes the index of the P group of basis vectors, or the first indication information includes the P group of basis vectors, or the protocol predefines a complete set of Q-dimensional basis vectors, and uses a bitmap or a combination number to indicate which M basis vectors are selected from the Q basis vectors for each group of basis vectors in the P group of basis vectors. For example, the protocol may predefine a complete set of Q-dimensional basis vectors, and the network device indicates the index of the P group of basis vectors through the first indication information, and the terminal device may select the P group of basis vectors according to the index of the P group of basis vectors.

[0009] In another possible implementation, the method further includes: receiving third indication information, wherein the third indication information is used to indicate X. With this implementation, the grouping method of the characteristic subspace beams may be indicated by the network device, or predefined by the protocol, or the network device indicates to select a grouping method from multiple grouping methods predefined by the protocol. After the network device indicates X, the terminal device may group the characteristic subspace beams according to the grouping method indicated by the network device or predefined by the protocol. The grouping method may be: for example, when X=2, it may be continuous grouping, with the first [N / 2] characteristic beams as one group and the last N-[N / 2] characteristic beams as another group, that is, N1=[N / 2], N2=N-[N / 2]. It may also be grouping according to the odd and even numbers of the characteristic subspace beams, with odd numbers as one group and even numbers as another group. Wherein, the number of characteristic subspace beams is N, and [.] indicates rounding up or down.

[0010] Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0011] Exemplarily, the first message and the second message may be the same message, or different messages.

[0012] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is It can be seen that the terminal device indicates X groups of basis vectors through the second indication information, and only needs to select basis vectors for characterizing the characteristic subspace beam from a limited group of basis vectors, thereby reducing the basis vector indication overhead for characterizing the characteristic subspace beam and reducing the processing complexity of the terminal device.

[0013] In another possible implementation, the method further includes: sending fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each group of characteristic subspace beams. With this implementation, the terminal device also feeds back the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, so that the network device can restore the characteristic subspace beams according to the X groups of basis vectors fed back by the terminal device and the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, thereby determining the precoding matrix based on the characteristic subspace beams and performing downlink data transmission based on the precoding matrix.

[0014] In a second aspect, a channel state information feedback method is provided, which is executed by a network device or a chip or circuit for a network device. The method includes: sending first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and the P and the M are positive integers greater than or equal to 1; and receiving second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and the X is a positive integer greater than or equal to 1. Using this method, the network device indicates the P groups of basis vectors to the terminal device, and the terminal device indicates the X groups of basis vectors to the network device, so that the terminal device only needs to select the basis vectors used to characterize the characteristic subspace beams from a limited group of basis vectors, thereby reducing the basis vector indication overhead used to characterize the characteristic subspace beams, and reducing the processing complexity of the terminal device.

[0015] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0016] In one possible implementation, the first indication information includes the index of the P group of basis vectors, or the first indication information includes the P group of basis vectors, or the protocol predefines a full set of Q-dimensional basis vectors, using a bit map or a combination number to indicate which M basis vectors are selected from the Q basis vectors for each group of basis vectors in the P group of basis vectors.

[0017] In another possible implementation, the method further includes: sending third indication information, wherein the third indication information is used to indicate the X.

[0018] Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0019] Exemplarily, the first message and the second message may be the same message, or different messages.

[0020] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is Bit.

[0021] In another possible implementation, the method further includes: receiving fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

[0022] In a third aspect, a channel state information feedback method is provided, which is executed by a terminal device or a chip or circuit for a terminal device. The method includes: receiving first indication information, wherein the first indication information is used to indicate K basis vectors, and K is a positive integer greater than or equal to 1; and sending second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, and the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, and each group of basis vectors in the X groups of basis vectors includes M basis vectors, and the M basis vectors belong to the K basis vectors, and the M≤K, and the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam. With this method, since the network device configures more basis vectors (but K is less than the number of basis vectors in the full set of basis vectors), a certain selection space is given to the UE, and a compromise between reporting overhead and feedback accuracy can be achieved.

[0023] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0024] In one possible implementation, the first indication information includes the index of the K basis vectors, or the first indication information includes the K basis vectors, or the protocol predefines a full set of Q-dimensional basis vectors, using a bit map or a combination number to indicate which K basis vectors are selected from the Q basis vectors.

[0025] In another possible implementation, the method further includes: receiving third indication information, wherein the third indication information is used to indicate X. With this implementation, the grouping method of the characteristic subspace beams may be indicated by the network device, or predefined by the protocol, or the network device indicates to select a grouping method from multiple grouping methods predefined by the protocol. After the network device indicates X, the terminal device may group the characteristic subspace beams according to the grouping method indicated by the network device or predefined by the protocol. The grouping method may be: for example, when X=2, it may be continuous grouping, with the first [N / 2] characteristic beams as one group and the last N-[N / 2] characteristic beams as another group, that is, N1=[N / 2], N2=N-[N / 2]. It may also be grouping according to the odd and even numbers of the characteristic subspace beams, with odd numbers as one group and even numbers as another group. The number of characteristic subspace beams is N.

[0026] Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0027] Exemplarily, the first message and the second message may be the same message, or different messages.

[0028] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is It can be seen that the terminal device indicates X groups of basis vectors through the second indication information, selects M from K basis vectors, K is less than the number of basis vectors in the entire basis vector set, and gives the UE a certain selection space, which can achieve a compromise between reporting overhead and feedback accuracy.

[0029] In another possible implementation, the method further includes: sending fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each group of characteristic subspace beams. With this implementation, the terminal device also feeds back the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, so that the network device can restore the characteristic subspace beams according to the X groups of basis vectors fed back by the terminal device and the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, thereby determining the precoding matrix based on the characteristic subspace beams and performing downlink data transmission based on the precoding matrix.

[0030] In a fourth aspect, a channel state information feedback method is provided, which is executed by a network device or a chip or circuit for a network device. The method includes: sending a first indication information, wherein the first indication information is used to indicate K basis vectors, and K is a positive integer greater than or equal to 1; and receiving a second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, and the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, and each group of basis vectors in the X groups of basis vectors includes M basis vectors, and the M basis vectors belong to the K basis vectors, and the M≤K, and the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam. With this method, since the network device configures more basis vectors (but K is less than the number of basis vectors in the full set of basis vectors), a certain selection space is given to the UE, and a compromise between reporting overhead and feedback accuracy can be achieved.

[0031] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0032] In one possible implementation, the first indication information includes the index of the K basis vectors, or the first indication information includes the K basis vectors, or the protocol predefines a full set of Q-dimensional basis vectors, using a bit map or a combination number to indicate which K basis vectors are selected from the Q basis vectors.

[0033] In another possible implementation, the method further includes: sending third indication information, wherein the third indication information is used to indicate the X.

[0034] Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0035] Exemplarily, the first message and the second message may be the same message, or different messages.

[0036] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is Bit.

[0037] In another possible implementation, the method further includes: receiving fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

[0038] The methods of the first and third aspects mentioned above can be executed by a terminal device, or by a module (such as a processor, chip, or chip system, etc.) applied to the terminal device, or by a logical node, logical module or software that can realize all or part of the functions of the terminal device.

[0039] The methods of the second and fourth aspects mentioned above can be executed by a network device, or by a module applied to the network device (such as a processor, chip, or chip system, etc.), or by a logical node, logical module or software that can realize all or part of the functions of the network device.

[0040] In a fifth aspect, a communication device is provided, for implementing the channel state information feedback method in the first aspect or any one of the implementations of the first aspect; or for implementing the channel state information feedback method in the third aspect or any one of the implementations of the third aspect. The device may be a terminal device, or a module (such as a processor, a chip, or a chip system) applied to a terminal device, or a logical node, a logical module, or software that can implement all or part of the functions of a terminal device.

[0041] In a sixth aspect, a communication device is provided, for implementing the channel state information feedback method in the second aspect or any one of the implementations of the second aspect; or for implementing the channel state information feedback method in the fourth aspect or any one of the implementations of the fourth aspect. The device may be a network device, or a module (such as a processor, a chip, or a chip system) applied to a network device, or a logical node, a logical module, or software that can implement all or part of the functions of a network device.

[0042] In a possible implementation, the communication device in the fifth to sixth aspects includes a module for respectively executing the method in any aspect or any implementation of the first to fourth aspects. Exemplarily, the communication device may include a sending unit, a receiving unit, and may also include a processing unit. The sending unit and the receiving unit may be independent or combined together (may be referred to as a "transceiver unit").

[0043] In another possible implementation, the communication device in the fifth to sixth aspects includes a processor coupled to a memory; the processor is configured to implement the device to perform the corresponding functions in the channel state information feedback method. The memory is used to couple with the processor, which stores the necessary programs (instructions) and / or data for the device. Optionally, the communication device may also include a communication interface for implementing communication between the device and other network elements. Optionally, the memory may be located inside the communication device or outside the communication device.

[0044] In another possible implementation, the communication device in the fifth to sixth aspects includes a processor and a transceiver, the processor is coupled to the transceiver, and the processor is used to execute a computer program or instruction to control the transceiver to receive and send information; when the processor executes the computer program or instruction, the processor is also used to implement the above method through a logic circuit or execute code instructions. The transceiver may be a transceiver, a transceiver circuit, an interface circuit or an input-output interface, which is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device. When the communication device is a chip, the transceiver is a transceiver circuit or an input-output interface.

[0045] When the communication device in the fifth to sixth aspects is a chip, the sending unit may be an output unit, such as an output circuit or a communication interface; the receiving unit may be an input unit, such as an input circuit or a communication interface. When the communication device is a terminal device or a network device, the sending unit may be a transmitter or a transmitter; the receiving unit may be a receiver or a receiver.

[0046] In a seventh aspect, a communication system is provided, which includes the communication device described in the fifth aspect and the communication device described in the sixth aspect.

[0047] In an eighth aspect, a chip is provided, wherein the chip is used to execute the methods described in the above aspects.

[0048] In a ninth aspect, a chip module is provided, including a transceiver component and a chip, wherein the chip is used to execute the methods described in the above aspects.

[0049] In a tenth aspect, a computer-readable storage medium is provided, wherein a computer program or instruction is stored in the computer-readable storage medium, and when the computer program or instruction is executed, the methods described in the above aspects are implemented.

[0050] In an eleventh aspect, a computer program product comprising instructions is provided. When the instructions are executed on a communication device, the communication device executes the methods described in the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A simplified schematic diagram of a wireless communication system provided by an embodiment of the present application;

[0052] Figure 2A to Figure 2D A schematic diagram of a network architecture provided for an embodiment of the present application;

[0053] Figure 3A basic flow chart of obtaining CSI for network equipment and UE;

[0054] Figure 4 Schematic diagram of the structure of the statistical feature subspace codebook in the space-frequency domain joint;

[0055] Figure 5 It is a schematic diagram of the quantization of statistical characteristic subspace beam projection;

[0056] Figure 6 A schematic diagram of a flow chart of a channel state information feedback method provided in an embodiment of the present application;

[0057] Figure 7 A schematic diagram of statistical feature subspace beam projection quantization in a case where X>1 is illustrated in an embodiment of the present application;

[0058] Figure 8 A schematic diagram of statistical feature subspace beam projection quantization in the case of X=1 in an example of an embodiment of the present application;

[0059] Fig. 9 A flow chart of another channel state information feedback method provided in an embodiment of the present application;

[0060] Fig.10 This is a schematic diagram of statistical feature subspace beam projection quantization in another case of X>1 in an example of an embodiment of the present application;

[0061] Fig.11 This is a schematic diagram of statistical feature subspace beam projection quantization in another case of X=1 according to an example of an embodiment of the present application;

[0062] Fig.12 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0063] Fig.13 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0065] The at least one (item) involved in the present application as follows indicates one (item) or more (items). More than one (item) refers to two (items) or more than two (items). "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. In addition, it should be understood that although the terms first, second, etc. may be used to describe each object in the present application, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0066] The terms "including" and "having" and any variations thereof mentioned in the following description of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units that are not listed, or optionally includes other steps or units that are inherent to these processes, methods, products or devices. It should be noted that in the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any method or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other methods or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0067] The technology provided by the present application can be applied to various communication systems. For example, the communication system can be a fourth generation (4 th The present invention relates to a 4G mobile communication system (such as a long term evolution (LTE) system), a 5G mobile communication system, a worldwide interoperability for microwave access (WiMAX) or a wireless local area network (WLAN) system, or a fusion system of multiple systems, or a future communication system, such as a sixth generation (6 th generation, 6G) mobile communication system, etc. Among them, the 5G mobile communication system can also be called a new radio (NR) system.

[0068] A network element in a communication system can send a signal to another network element or receive a signal from another network element. The signal may include information, signaling, or data, etc. The network element may also be replaced by an entity, a network entity, a device, a terminal device, a communication module, a node, a communication node, etc. The network element is used as an example for description in this application. For example, a communication system may include at least one terminal device and at least one access network device. The access network device may send a downlink signal to the terminal device, and / or the terminal device may send an uplink signal to the access network device. In addition, it can be understood that if a plurality of terminal devices are included in the communication system, the plurality of terminal devices may also send signals to each other, that is, the signal sending network element and the signal receiving network element may both be terminal devices.

[0069] See also Figure 1 , Figure 1 A simplified schematic diagram of a wireless communication system provided in an embodiment of the present application. Figure 1 As shown, the wireless communication system includes a wireless access network 100. The wireless access network 100 may be a next generation (e.g., 6G or higher) wireless access network, or a traditional (e.g., 5G, 4G) wireless access network. One or more terminal devices (120a-120j, collectively referred to as 120) may be connected to each other, or to one or more network devices (110a, 110b, collectively referred to as 110) in the wireless access network 100. Optionally, Figure 1 This is just a schematic diagram. The wireless communication system may also include other devices, such as core network devices, wireless relay devices and / or wireless backhaul devices. Figure 1 Not drawn in.

[0070] Optionally, in practical applications, the wireless communication system may include multiple network devices (also referred to as access network devices) at the same time, and may also include multiple terminal devices at the same time. A network device may serve one or more terminal devices at the same time. A terminal device may also access one or more network devices at the same time. The embodiment of the present application does not limit the number of terminal devices and network devices included in the wireless communication system.

[0071] The network device may be an entity on the network side for transmitting or receiving signals. The network device may be an access device for a terminal device to access the wireless communication system in a wireless manner, such as a base station. The base station can broadly cover the following various names, or be replaced with the following names, such as: radio access network (RAN) node, node B (NodeB), evolved NodeB (eNB), next generation NodeB (gNB), access network equipment in open radio access network (O-RAN), relay station, access point, transmission point (transmitting and receiving point, TRP), transmission point (transmitting point, TP), master eNB (MeNB), secondary eNB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), distributed unit (distributed The base station may be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The network device may also refer to a communication module, a modem or a chip that is arranged in the aforementioned device or apparatus. The network device may also be a mobile switching center and a device that performs the base station function in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network side device in a 6G network, and a device that performs the base station function in a future communication system. The network device may support networks with the same or different access technologies. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

[0072] The network equipment may be fixed or mobile. For example, the base stations 110 a and 110 b are stationary and are responsible for wireless transmission and reception in one or more cells from the terminal equipment 120 . Figure 1 The helicopter or drone 120i shown in the figure can be configured to act as a mobile base station, and one or more cells can move according to the location of the mobile base station 120i. In other examples, the helicopter or drone (120i) can be configured to act as a terminal device communicating with the base station 110b.

[0073] In the present application, the communication device used to implement the above access network function can be an access network device, or a network device with some functions of accessing the network, or a device capable of supporting the implementation of the access network function, such as a chip system, a hardware circuit, a software module, or a hardware circuit plus a software module, which can be installed in the access network device or used in combination with the access network device. In the method of the present application, the communication device used to implement the access network device function is an access network device for example.

[0074] The terminal device can be an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal device can be used to connect people, objects and machines. The terminal device can communicate with one or more core networks through a network device. The terminal device includes a handheld device with a wireless connection function, other processing devices connected to a wireless modem, or a vehicle-mounted device. The terminal device can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device. The terminal device 120 can be widely used in various scenarios, such as cellular communication, D2D, V2X, point-to-point (P2P), machine-to-machine (M2M), machine type communication (MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, drone, robot, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.Some examples of terminal devices 120 are: user equipment (UE) of 3GPP standard, fixed equipment, mobile devices, handheld devices, wearable devices, cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal computers, smart books, vehicles, satellites, global positioning system (GPS) devices, target tracking devices, drones, helicopters, aircraft, ships, remote control devices, smart home devices, industrial equipment, personal communication service (PCS) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), wireless network cameras, tablet computers, PDAs, mobile internet devices (MIDs), wearable devices such as smart watches, VR devices, AR devices, wireless terminals in industrial control, terminals in vehicle networking systems, wireless terminals in self-driving, wireless terminals in smart grids, wireless terminals in transportation safety, and smart cities. The terminal device 120 may be a wireless terminal in a smart city, such as a smart gas pump, a terminal device on a high-speed rail, and a wireless terminal in a smart home, such as a smart speaker, a smart coffee machine, a smart printer, etc. The terminal device 120 may be a wireless device in the above various scenarios or a device used to be set in a wireless device, for example, a communication module, a modem or a chip in the above device. The terminal device may also be referred to as a terminal, a terminal device, a user equipment (UE), a mobile station (MS), a mobile terminal (MT), etc. The terminal device may also be a terminal device in a future wireless communication system. The terminal device may be used in a dedicated network device or a general device. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0075] Optionally, the terminal device may be used to act as a base station. For example, the UE may act as a scheduling entity that provides sidelink signals between UEs in V2X, D2D, or P2P, etc. Figure 1As shown, the cell phone 120a and the car 120b communicate with each other using a sidelink signal. The cell phone 120a and the smart home device 120e communicate with each other without relaying the communication signal through the base station 110b.

[0076] In the present application, the communication device for realizing the functions of the terminal device may be a terminal device, or a terminal device having some functions of the above terminal devices, or a device capable of supporting the functions of the above terminal devices, such as a chip system, which may be installed in the terminal device or used in combination with the terminal device. In the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. In the technical solution provided in the present application, the communication device is described as a terminal device or UE as an example.

[0077] Optionally, a wireless communication system is usually composed of cells, and the base station provides management of the cell. The base station provides communication services to multiple mobile stations (MS) in the cell. The base station includes a baseband unit (BBU) and a remote radio unit (RRU). The BBU and RRU can be placed in different places, for example: the RRU is remote and placed in an area with high traffic volume, and the BBU is placed in a central computer room. The BBU and RRU can also be placed in the same computer room. The BBU and RRU can also be different components under one rack. Optionally, a cell can correspond to a carrier or a component carrier.

[0078] In some deployments, the network device mentioned in the embodiments of the present application may be a device including a CU, or a DU, or a device including a CU and a DU, or a control plane CU node (central unit control plane (central unit-control plane, CU-CP)) and a user plane CU node (central unit user plane (central unit-user plane, CU-UP)) and a DU node. For example, the network device may include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0079] In some deployments, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes implement part of the functions of the base station. For example, the RAN node can be a CU, DU, CU-CP, CU-UP, or RU. The CU and DU can be set separately, or can also be included in the same network element, such as a BBU. The RU can be included in a radio frequency device or a radio frequency unit, such as an RRU, AAU, or RRH.

[0080] The RAN node may support one or more types of fronthaul interfaces, and different fronthaul interfaces correspond to DUs and RUs with different functions. If the fronthaul interface between the DU and the RU is a common public radio interface (CPRI), the DU is configured to implement one or more baseband functions, and the RU is configured to implement one or more radio frequency functions. If the fronthaul interface between the DU and the RU is another interface, relative to the CPRI, part of the downlink and / or uplink baseband functions, such as, for downlink, one or more of precoding, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / adding cyclic prefix (CP), are moved from the DU to the RU for implementation, and for uplink, one or more of digital beamforming (BF), or fast Fourier transform (IFFT) / removing cyclic prefix (CP), are moved from the DU to the RU for implementation. In a possible implementation, the interface may be an enhanced common public radio interface (eCPRI). In the eCPRI architecture, the division between DU and RU is different, corresponding to different types (category, Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, F.

[0081] Taking eCPRI Cat A as an example, for downlink transmission, based on layer mapping, the DU is configured to implement layer mapping and one or more functions before it (i.e., one or more functions of coding, rate matching, scrambling, modulation, and layer mapping), while other functions after layer mapping (e.g., RE mapping, digital beamforming (BF), or one or more functions of inverse fast Fourier transform (IFFT) / adding cyclic prefix (CP)) are moved to the RU for implementation. For uplink transmission, based on de-RE mapping, the DU is configured to implement de-mapping and one or more functions before it (i.e., one or more functions of decoding, de-rate matching, de-scrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping), while other functions after de-mapping (e.g., one or more functions of digital BF or fast Fourier transform (FFT) / removing CP) are moved to the RU for implementation. It can be understood that for the functional description of DU and RU corresponding to various types of eCPRI, reference can be made to the eCPRI protocol and will not be repeated here.

[0082] In one possible design, the processing unit for implementing the baseband function in the BBU is called a baseband high layer (BBH) unit, and the processing unit for implementing the baseband function in the RRU / AAU / RRH is called a baseband low layer (BBL) unit.

[0083] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. Any unit in the CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0084] In the embodiments of the present application, the device for realizing the function of the network device may be a network device; or it may be a device capable of supporting the network device to realize the function, such as a chip system, a hardware circuit, a software module, or a hardware circuit plus a software module. The device may be installed in the network device or used in combination with the network device. In the embodiments of the present application, only the device for realizing the function of the network device is a network device as an example for explanation, and the scheme of the embodiments of the present application is not limited.

[0085] It can be understood that the present application can be applied between network devices and terminal devices.

[0086] The communication between the network device and the terminal device follows a certain protocol layer structure. The protocol layer structure may include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure may include the functions of the protocol layers such as the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer and the physical layer. For example, the user plane protocol layer structure may include the functions of the protocol layers such as the PDCP layer, the RLC layer, the MAC layer and the physical layer. In a possible implementation, the service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0087] Optionally, the protocol layer structure between the network device and the terminal device may also include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0088] Taking data transmission between network devices and terminal devices as an example, data transmission needs to pass through the user plane protocol layer, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. Among them, the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer can also be collectively referred to as the access layer. According to the transmission direction of the data, it is divided into sending or receiving, and each of the above layers is divided into a sending part and a receiving part. Taking downlink data transmission as an example, after the PDCP layer obtains data from the upper layer, it transmits the data to the RLC layer and the MAC layer, and then the MAC layer generates a transmission block, and then transmits it wirelessly through the physical layer. The data is encapsulated accordingly in each layer. For example, the data received by a layer from the upper layer of the layer is regarded as the service data unit (SDU) of the layer, which becomes a protocol data unit (PDU) after being encapsulated by the layer, and then passed to the next layer.

[0089] Exemplarily, the terminal device may also have an application layer and a non-access layer. The application layer may be used to provide services to applications installed in the terminal device. For example, downlink data received by the terminal device may be sequentially transmitted from the physical layer to the application layer, and then provided to the application by the application layer; for another example, the application layer may obtain data generated by the application, and sequentially transmit the data to the physical layer and send it to other communication devices. The non-access layer may be used to forward user data, such as forwarding uplink data received from the application layer to the SDAP layer, or forwarding downlink data received from the SDAP layer to the application layer.

[0090] In order to support AI technology in wireless networks, AI nodes may also be introduced into the network.

[0091] Optionally, the AI ​​node can be deployed in one or more of the following locations in the communication system: access network equipment, terminal equipment, or core network equipment, etc., or the AI ​​node can also be deployed separately, for example, deployed in a location other than any of the above devices, such as a host or cloud server in an over the top (OTT) system. The AI ​​node can communicate with other devices in the communication system, and the other devices can be, for example, one or more of the following: network equipment, terminal equipment, or network elements of the core network, etc.

[0092] It is understood that the present application does not limit the number of AI nodes. For example, when there are multiple AI nodes, the multiple AI nodes can be divided based on functions, such as different AI nodes are responsible for different functions.

[0093] It can also be understood that AI nodes can be independent devices, or they can be integrated into the same device to implement different functions, or they can be network elements in hardware devices, or they can be software functions running on dedicated hardware, or they can be virtualized functions instantiated on a platform (for example, a cloud platform). This application does not limit the specific form of the above-mentioned AI nodes.

[0094] An AI node can be an AI network element or an AI module.

[0095] One or more AI modules are provided in one or more devices of these network element nodes, such as core network equipment, access network nodes (RAN nodes), terminals or OAM. The access network node can be a separate RAN node, or it can include multiple RAN nodes, for example, including CU and DU. The CU and / or DU can also be provided with one or more AI modules. Optionally, the CU can also be split into CU-CP and CU-UP. One or more AI models are provided in the CU-CP and / or CU-UP.

[0096] The AI ​​module is used to implement the corresponding AI function. The AI ​​modules deployed in different network elements can be the same or different. The model of the AI ​​module can implement different functions according to different parameter configurations. The model of the AI ​​module can be configured based on one or more of the following parameters: structural parameters (such as the number of neural network layers, the width of the neural network, the connection relationship between layers, the weight of the neuron, the activation function of the neuron, or at least one of the biases in the activation function), input parameters (such as the type of input parameters and / or the dimension of input parameters), or output parameters (such as the type of output parameters and / or the dimension of output parameters). Among them, the bias in the activation function can also be called the bias of the neural network.

[0097] An AI module can have one or more models. A model can be inferred to obtain an output, which includes one parameter or multiple parameters. The learning process, training process, or inference process of different models can be deployed in different nodes or devices, or can be deployed in the same node or device.

[0098] The communication system includes a RAN intelligent controller (RIC). For example, the RIC may be the above-mentioned AI module, which is used to implement AI-related functions. The RIC includes a near-real time RIC (near-real time RIC, near-RT RIC) and a non-real time RIC (non-real time RIC, Non-RT RIC). Among them, the non-real time RIC mainly processes non-real-time information, such as data that is not sensitive to delay, and the delay of the data may be in the order of seconds. The real-time RIC mainly processes near-real-time information, such as data that is relatively sensitive to delay, and the delay of the data is in the order of tens of milliseconds.

[0099] Near real-time RIC is used for model training and reasoning. For example, it is used to train an AI model and use the AI ​​model for reasoning. Near real-time RIC can obtain information on the network side and / or the terminal side from RAN nodes (such as CU, CU-CP, CU-UP, DU and / or RU) and / or terminals. This information can be used as training data or reasoning data. Optionally, near real-time RIC can submit the reasoning results to the RAN node and / or terminal. Optionally, the reasoning results can be exchanged between the CU and DU, and / or between the DU and RU. For example, the near real-time RIC submits the reasoning results to the DU, and the DU sends it to the RU.

[0100] Non-real-time RIC is also used for model training and reasoning. For example, it is used to train an AI model and use the model for reasoning. Non-real-time RIC can obtain information on the network side and / or the terminal side from RAN nodes (such as CU, CU-CP, CU-UP, DU and / or RU) and / or terminals. This information can be used as training data or reasoning data, and the reasoning results can be submitted to the RAN node and / or the terminal. Optionally, the reasoning results can be exchanged between the CU and the DU, and / or between the DU and the RU. For example, the non-real-time RIC submits the reasoning results to the DU, and the DU sends it to the RU.

[0101] The near real-time RIC and the non-real-time RIC may also be separately set as a network element. Optionally, the near real-time RIC and the non-real-time RIC may also be part of other devices, for example, the near real-time RIC is set in a RAN node (for example, in a CU or DU), and the non-real-time RIC is set in an OAM, a cloud server, a core network device, or other network devices.

[0102] For example, the configuration of near real-time RIC and non-real-time RIC in the network architecture can be as follows: Figure 2A to Figure 2D As shown:

[0103] like Figure 2AAs shown in (a), in a first possible implementation, the access network device includes a near real-time RIC module for model learning and / or reasoning.

[0104] like Figure 2A As shown in (b), in a second possible implementation, in a communication system, a non-real-time RIC may be included outside the access network device. Optionally, the non-real-time RIC may be located in the OAM or in the core network device.

[0105] like Figure 2A As shown in (c), in a third possible implementation, the access network device includes a near real-time RIC, and the access network device also includes a non-real-time RIC. Optionally, the non-real-time RIC may be located in the OAM or in the core network device.

[0106] relatively Figure 2A (c) in Figure 2B The CU is separated into CU-CP and CU-UP. The near real-time RIC and non-real-time RIC are set in Figure 2A Same as (c) in .

[0107] like Figure 2C As shown, optionally, the access network device includes one or more AI entities, and the function of the AI ​​entity is similar to the above-mentioned near real-time RIC. Optionally, the OAM includes one or more AI entities, and the function of the AI ​​entity is similar to the above-mentioned non-real-time RIC. Optionally, the core network device includes one or more AI entities, and the function of the AI ​​entity is similar to the above-mentioned non-real-time RIC. When both the OAM and the core network device include AI entities, the models trained by their respective AI entities are different, and / or the models used for reasoning are different. In the present application, the difference in models may include at least one of the following differences: structural parameters of the model (such as the number of layers of the model, and / or weights, etc.), input parameters of the model, or output parameters of the model.

[0108] relatively Figure 2C , Figure 2D The access network devices in the embodiment are separated into CU and DU. Optionally, the CU may include an AI entity, and the function of the AI ​​entity is similar to the above-mentioned near real-time RIC. Optionally, the DU may include an AI entity, and the function of the AI ​​entity is similar to the above-mentioned near real-time RIC. When both the CU and the DU include AI entities, the models trained by their respective AI entities are different, and / or the models used for reasoning are different. Optionally, the Figure 2D The CU in the CU is split into CU-CP and CU-UP. Optionally, one or more AI models can be deployed in the CU-CP. And / or, one or more AI models can be deployed in the CU-UP. Optionally, Figure 2C or Figure 2DIn the example, the OAM of access network equipment and the OAM of core network equipment can be deployed separately and independently.

[0109] It should be understood that Figure 1 The number and type of each device in the communication system shown are for illustration only, and the present application is not limited thereto. In actual applications, the communication system may also include more terminal devices, more access network devices, and other network elements, such as core network devices, and / or network elements for implementing artificial intelligence functions.

[0110] It is understandable that all or part of the functions implemented by one or more of the terminal equipment, access network equipment, core network equipment, or network elements used to implement artificial intelligence functions can be virtualized, that is, implemented by one or more of the proprietary processors or general-purpose processors and the corresponding software modules. Among them, the terminal equipment and the access network equipment involve interfaces for air interface transmission, and the transceiver functions of the interfaces can be implemented by hardware. Core network equipment, such as operation administration and maintenance (OAM) network elements, can be virtualized. Optionally, one or more functions of the virtualized terminal equipment, access network equipment, core network equipment, or network elements used to implement artificial intelligence functions can be implemented by cloud devices, such as cloud devices in over the top (OTT) systems.

[0111] Embodiments of the present application relate to channel measurement and feedback. In time division duplexing (TDD) mode, uplink and downlink channels transmit signals on different time resources of the same frequency domain resources. Within a relatively short time (coherence time of channel propagation), it can be considered that the channel fading experienced by the signals on the uplink and downlink channels is the same, and therefore has reciprocity. Network equipment can use channel reciprocity to obtain the CSI of the downlink channel through the uplink channel, and then perform precoding.

[0112] In FDD mode, the frequency band interval of the uplink and downlink channels is much larger than the coherent bandwidth, and the uplink and downlink channels do not have complete reciprocity. In traditional FDD systems, users are required to feedback the CSI of the downlink channel to the network equipment, such as Figure 3The basic flow diagram of the network device and UE obtaining CSI is shown. The flow includes the following steps: S301. The network device sends channel measurement configuration information to the UE to inform the UE of the time and behavior of channel measurement; then, S302. The network device sends a channel measurement pilot to the UE for channel measurement; S303. The UE performs measurement according to the pilot sent by the network device, calculates the final CSI feedback amount, and feeds back the CSI to the network device; S304. The network device then sends data according to the CSI fed back by the UE. Among them, the network device determines the number of streams for transmitting data to the UE according to the channel rank indicator (RI) fed back by the UE; the network device determines the modulation order of the data transmitted to the UE and the code rate of the channel coding according to the channel quality indicator (CQI) fed back by the UE; the network device determines the precoding of the data transmitted to the UE according to the PMI fed back by the UE.

[0113] PMI feedback is determined and reported based on a set of codebooks. The design of the FDD CSI codebook is a basic and important issue in the 5G mobile communication system. At present, FDD CSI feedback uses the information on the network device side as a reference for channel quantization, and the PMI fed back by the UE is determined based on the main eigenvector of the channel with the network device side as the transmitter. The version (release, Rel-) 15 Type II codebook adopts the idea of ​​spatial domain (angle) compression, and represents the main eigenvector (i.e., the precoding matrix of a single user) with a linear combination of several discrete Fourier transform (DFT) basis vectors in the spatial domain. Based on the R15 codebook, the Rel-16 Type II codebook further compresses the frequency domain (delay) by using the frequency domain correlation of the amplitude and phase coefficients of different subbands, and represents the main eigenvector with a bilinear combination of several spatial domain DFT basis vectors and several frequency domain DFT basis vectors. In order to make full use of the sparsity of the channel in the space-frequency domain and further improve the accuracy of PMI feedback, a codebook based on statistical feature subspace is proposed. The codebook uses a linear combination of feature subspace beams with long-period statistics to approximate the downlink channel or the main feature vector of the downlink channel. The codebook can be similar to the Rel-16 Type II codebook, where the space domain and frequency domain are each represented by a set of statistical feature subspace beams in the form of bilinear combination, or it can be represented by a set of linear combination of feature subspace beams in the space-frequency domain, such as Figure 4The schematic diagram of the structure of the space-frequency domain joint statistical characteristic subspace codebook is shown. For this type of codebook, the UE needs to feedback the statistical characteristic subspace beam in the long period and the beam superposition coefficient in the short period. If the scalar quantization method is used to directly feedback the elements of the long-period feedback statistical characteristic subspace beam, the feedback overhead is large. How to feedback the long-period statistical characteristic subspace beam with low overhead is the key issue of this type of codebook.

[0114] To solve the long-period feedback problem of the statistical characteristic subspace beam, the projection quantization scheme is currently used, which approximates each beam in the statistical characteristic subspace beam set with a linear combination of the same set of DFT basis vectors, such as Figure 5 The schematic diagram of the statistical characteristic subspace beam projection quantization is shown in Figure 2, where N t *N f represents the dimension of the statistical feature subspace beam, N is the number of statistical feature subspace beams, and M is the number of selected DFT basis vectors. With this projection quantization scheme, the UE does not need to directly report the number of (N t *N f )×N elements, only the indices of M DFT basis vectors and M×N combination coefficients need to be reported, which can reduce the feedback overhead to a certain extent.

[0115] However, since the DFT basis vectors used to quantize the eigenbeams have a large dimension, there are still problems such as high processing complexity and high reporting overhead when selecting and reporting the DFT basis vectors on the UE side. t =16,N f =13, M = 32, for example, it contains 16*13=208 DFT vectors with a dimension of 208×1, which needs to be bits to indicate the M DFT basis vectors used for statistical eigenvalue subspace beam projection quantization. On the other hand, because all eigenvalue beams use the same set of basis vectors for projection, the projection quantization accuracy of the eigenvalue beam is limited, which in turn affects the overall accuracy of PMI feedback. The linear / bilinear combination of statistical eigenvalue subspace beams cannot approximate the downlink channel or main eigenvalue vector very well.

[0116] The above scheme does not fully consider the problem of high feedback overhead caused by the large dimension of the basis vector used for eigenbeam projection quantization. How to use the partial reciprocity of FDD uplink and downlink channels to report statistical eigenbeams with as little feedback overhead as possible without losing accuracy is an urgent problem to be solved for this type of codebook based on statistical eigenbeams.

[0117] In view of this, the present application provides a communication solution, wherein a network device sends indication information of P groups of basis vectors to a terminal device; and the terminal device sends indication information of X groups of basis vectors in the P groups of basis vectors to the network device according to the indication information, wherein the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, and each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam. Thus, the terminal device only needs to select basis vectors for characterizing characteristic subspace beams from a limited group of basis vectors, thereby reducing the basis vector indication overhead for characterizing characteristic subspace beams, and at the same time reducing the processing complexity of the terminal device.

[0118] In this application, "sending information to... (e.g., UE)" or the related illustrations in the accompanying drawings can be understood as the destination end of the information is the UE. It can include sending information to the UE directly or indirectly. "Receiving information from... (e.g., UE)" or "receiving information from... (e.g., UE)", or the related illustrations in the accompanying drawings can be understood as the source end of the information is the UE, which can include receiving information from the UE directly or indirectly. The information may be processed as necessary between the source end and the destination end of the information transmission, such as format changes, etc., but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be repeated here.

[0119] The channel state information feedback method provided by the embodiment of the present application is described in detail below. It can be understood that the present application uses the UE and the network device as an example to illustrate the execution subject of the interaction, but the present application does not limit the execution subject of the interaction. For example, the UE in the method provided by the present application may also be a chip, a chip system, or a processor applied to the UE, or a logical node, a logical module, or software that can implement all or part of the UE; the network device in the method provided by the present application may also be a chip, a chip system, or a processor applied to the network device, or a logical node, a logical module, or software that can implement all or part of the network device function.

[0120] like Figure 6 FIG. 1 is a flow chart of a channel state information feedback method provided in an embodiment of the present application. Exemplarily, the method may include the following steps:

[0121] S601. The network device sends first indication information to the UE. Correspondingly, the UE receives the first indication information.

[0122] In FDD mode, the frequency band interval of the uplink and downlink channels is much larger than the coherence bandwidth, and the uplink and downlink channels have partial reciprocity, such as angle reciprocity and delay reciprocity. Based on the partial reciprocity of the uplink and downlink channels, the network device pre-weights the downlink pilot signal to obtain one or more groups of basis vectors. In addition, this scheme is based on a codebook of statistical characteristic subspaces, which uses a linear combination of characteristic subspace beams with long-period statistics to approximate the main eigenvectors of the downlink channel. Therefore, in this embodiment, the network device configures one or more groups of basis vectors through signaling for the UE to select and project the quantized characteristic subspace beams.

[0123] In this step, the network device sends first indication information to the UE. The first indication information is used to indicate the configuration of a basis vector group of a statistical characteristic subspace beam (referred to as "characteristic subspace beam"). Exemplarily, the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and P and M are positive integers greater than or equal to 1.

[0124] The first indication information is used to indicate the P groups of basis vectors, and can be implemented in the following two ways:

[0125] In one implementation, the first indication information includes the index of the P groups of basis vectors. The protocol predefines a complete set of Q-dimensional basis vectors (including Q basis vectors), and each group of basis vectors indicated by the network device through the first indication information is selected from the complete set of Q-dimensional basis vectors predefine by the protocol, and the index of the P groups of basis vectors is indicated. For example, the basis vectors may be DFT basis vectors.

[0126] In another implementation, the first indication information includes P groups of basis vectors, that is, the network device directly configures the P groups of basis vectors to the UE, that is, sends the specific value of each basis vector in the P groups of basis vectors to the UE.

[0127] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0128] In another implementation, a protocol may predefine a complete set of Q-dimensional basis vectors, and use a bitmap or a combination number to indicate which M basis vectors are selected from the Q basis vectors for each group of P groups of basis vectors.

[0129] In another example, the value of P may also be indicated by the UE through a UE capability parameter or predefined by the protocol.

[0130] S602. The UE sends second indication information to the network device according to the first indication information. Correspondingly, the network device receives the second indication information.

[0131] After receiving the first indication information, the UE divides the characteristic subspace beams into X groups (X=1 or X>1), selects X groups of basis vectors from the P groups of basis vectors for projected quantization of N characteristic subspace beams, where N is a positive integer greater than or equal to 1. The X groups of basis vectors are respectively used to characterize the X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1. Then, the UE sends the second indication information to the network device. The second indication information is used to indicate the X groups of basis vectors selected by the UE.

[0132] Exemplarily, before step S602, the network device may further send third indication information to the terminal device. The third indication information is used to indicate the grouping configuration indication of the characteristic subspace beam. Exemplarily, the third indication information is used to indicate the above-mentioned X. Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, DCI. The second message and the above-mentioned first message may be the same message, or different messages.

[0133] In another example, X may also be determined by the UE or predefined by the protocol.

[0134] The grouping method of the characteristic subspace beams may be indicated by the network device, or predefined by the protocol, or the network device may indicate that a grouping method is selected from multiple grouping methods predefined by the protocol. After the network device indicates X, the terminal device may group the characteristic subspace beams according to the grouping method indicated by the network device or predefined by the protocol. The grouping method may be: for example, when X=2, it may be continuous grouping, with the first [N / 2] characteristic beams as one group and the last N-[N / 2] characteristic beams as another group, that is, N1=[N / 2], N2=N-[N / 2]. It may also be grouped according to the odd and even numbers of the characteristic subspace beams, with odd numbers as one group and even numbers as another group. The number of characteristic subspace beams is N.

[0135] After receiving the second indication information, the network device can reconstruct the downlink channel in combination with the angle and delay information estimated through the uplink channel.

[0136] Furthermore, the method may also include the following steps (this step is optional and is indicated by a dotted line in the figure):

[0137] S603. The UE sends fourth indication information to the network device. Correspondingly, the network device receives the fourth indication information.

[0138] The fourth indication information is used to indicate the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors is M*Ni , where 1≤i≤X, N i is the number of beams in each set of characteristic subspace beams.

[0139] The above method is further described below by an example. In this example, there are N characteristic subspace beams, the dimension of each beam in the N beams is Q, and the statistical characteristic subspace beams are represented by a matrix B. According to the uplink channel measurement results and based on the partial reciprocity of the uplink and downlink channels, the network device configures P groups of candidate basis vectors for the UE, such as DFT basis vectors, represented by the matrix , where 1≤p≤P and p is a positive integer. Each of the P groups of basis vectors includes M basis vectors, where M is a positive integer greater than or equal to 1, and the dimension of each of the M basis vectors is Q. The UE selects X groups (X=1 or X>1) from the P groups for the projected quantization of the N characteristic subspace beams. Figure 7 As shown, it is a schematic diagram of statistical feature subspace beam projection quantization in the case of X>1 in an example of an embodiment of the present application, where X>1 means that N feature subspace beams are divided into X groups, and each group of feature subspace beams selects a group of basis vectors from P groups of basis vectors for projection quantization; Figure 8 As shown, it is a schematic diagram of statistical characteristic subspace beam projection quantization in the case of X=1 in an example of an embodiment of the present application. X=1 means that N characteristic subspace beams do not need to be grouped, and a group of basis vectors are selected from P groups of basis vectors for projection quantization.

[0140] exist Figure 7 In the above example, N characteristic subspace beams are divided into X groups. The dimension of each beam in each group of characteristic subspace beams is Q. Each group of characteristic subspace beams includes N i The number of beams included in each set of characteristic subspace beams in the X sets of characteristic subspace beams can be the same or different. Each set of characteristic subspace beams is represented by the matrix UE selects X groups of basis vectors from P groups of candidate basis vectors. The X groups of basis vectors are used to represent the X groups of characteristic subspace beams, and each group of basis vectors in the X groups of basis vectors also includes M basis vectors. Each group of basis vectors in the X groups of basis vectors belongs to P groups of basis vectors. The dimension of the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors is M*N i In this case, the long-term reporting volume is In addition, as a special case, when X = N, each characteristic subspace beam is a group, and each characteristic subspace beam selects a group of basis vectors from P groups of basis vectors for projection quantization. The long-term reporting amount is Bit.

[0141] exist Figure 8In the above example, the N feature subspace beams do not need to be grouped and the same set of basis vectors are used for projection quantization. The UE selects one set of basis vectors from the P sets of candidate basis vectors. The selected set of basis vectors includes M basis vectors, each of which has a dimension of Q. The dimension of the combination coefficients corresponding to the set of basis vectors is M*N (using the matrix C 13 In this case, the long-term reporting amount is In addition, as a special case, if the network device configures a set of basis vectors (P=X=1), the UE does not need to select basis vectors, and directly uses the basis vectors configured by the network device for the projection quantization of all eigensubspace beams.

[0142] According to a channel state information feedback method provided by an embodiment of the present application, a network device sends indication information of P groups of basis vectors to a terminal device; and the terminal device sends indication information of X groups of basis vectors in the P groups of basis vectors to the network device according to the indication information, and the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, and each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam. Thus, the terminal device only needs to select the basis vectors used to characterize the characteristic subspace beams from a limited group of basis vectors, which reduces the basis vector indication overhead used to characterize the characteristic subspace beams, and at the same time reduces the processing complexity of the terminal device;

[0143] In this embodiment, the statistical characteristic subspace beams are divided into X groups, and each group of beams is approximately represented by a linear combination of a group of basis vectors. Figure 5 As shown, each beam in the statistical characteristic subspace beam set is approximately characterized by a linear combination of the same set of basis vectors, which also improves the projection quantization accuracy of the characteristic beam, thereby improving the overall feedback accuracy of the PMI.

[0144] However, due to the limited reciprocity of the uplink and downlink space-frequency parts, the basis vectors pre-configured by the network device may differ from the actual needs of the UE. Therefore, the present application also provides another communication scheme, in which the network device sends a first indication message to the terminal device; and the terminal device sends a second indication message to the network device according to the first indication message, and the second indication message is used to indicate X groups of basis vectors, and the X groups of basis vectors are used to characterize X groups of characteristic subspace beams, respectively, and each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam. Among them, the first indication message is used to indicate K basis vectors, K is a positive integer greater than or equal to 1, and each group of basis vectors in the X groups of basis vectors includes M basis vectors, and the M basis vectors belong to K basis vectors, M≤K. Since the number of basis vectors K in the basis vectors configured by the network device is greater than the number M actually used by the UE, that is, the network device configures more basis vectors (but K is less than the number of basis vectors in the full set), a certain selection space is given to the UE, and a compromise between reporting overhead and feedback accuracy can be achieved.

[0145] like Fig. 9 FIG. 1 is a flow chart of another channel state information feedback method provided in an embodiment of the present application. Exemplarily, the method may include the following steps:

[0146] S901. The network device sends first indication information to the UE. Correspondingly, the UE receives the first indication information.

[0147] In this embodiment, the network device configures multiple basis vectors through signaling for the UE to select and project the quantized characteristic subspace beam. Exemplarily, the network device sends a first indication message to the UE. Exemplarily, the network device sends a first indication message to the UE. The first indication message is used to indicate the basis vector configuration of the characteristic subspace beam. Exemplarily, the first indication message is used to indicate K basis vectors, where K is a positive integer greater than or equal to 1. Exemplarily, the basis vector is a DFT basis vector.

[0148] The first indication information is used to indicate K basis vectors, and can be implemented in the following two ways:

[0149] In one implementation, the first indication information includes the indexes of the K basis vectors. The protocol predefines a Q-dimensional full set (including Q basis vectors), and the K basis vectors indicated by the network device through the first indication information are all selected from the Q-dimensional full set predefine by the protocol, and the indexes of the K basis vectors are indicated.

[0150] In another implementation, the first indication information includes K basis vectors, that is, the network device directly configures the K basis vectors to the UE, that is, sends the specific value of each basis vector in the K basis vectors to the UE.

[0151] Exemplarily, the first indication information is carried in a first message, and the first message includes at least one of the following: RRC signaling, MAC-CE, and DCI.

[0152] In yet another implementation, a protocol may predefine a complete set of Q-dimensional basis vectors, and use a bitmap or a combination number to indicate which K basis vectors to select from the Q basis vectors.

[0153] In another example, the value of K may also be indicated by the UE through a UE capability parameter or predefined by the protocol.

[0154] S902. The UE sends second indication information to the network device according to the first indication information. Correspondingly, the network device receives the second indication information.

[0155] After receiving the first indication information, the UE divides the N characteristic subspace beams into X groups (X=1 or X>1), where N is a positive integer greater than or equal to 1. For each group of characteristic subspace beams, M basis vectors are selected from the K basis vectors for projection quantization of the group of characteristic subspace beams, and M is a positive integer greater than or equal to 1. The X groups of basis vectors are used to characterize the X groups of characteristic subspace beams, each group of basis vectors in the X groups of basis vectors includes M basis vectors, the M basis vectors belong to K basis vectors, M≤K, and each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1. Then, the UE sends a second indication information to the network device. The second indication information is used to indicate the X groups of basis vectors selected by the UE.

[0156] Exemplarily, the M basis vectors selected by the UE for each group of characteristic subspace beams may be completely different, or partially the same, or completely the same.

[0157] Exemplarily, before step S902, the network device may further send third indication information to the terminal device. The third indication information is used to indicate the grouping configuration indication of the characteristic subspace beam. Exemplarily, the third indication information is used to indicate the above-mentioned X. Exemplarily, the third indication information is carried in a second message, and the second message includes at least one of the following: RRC signaling, MAC-CE, DCI. Exemplarily, the second message and the above-mentioned first message may be the same message, or different messages.

[0158] In another example, X may also be indicated by the UE or predefined by the protocol.

[0159] The grouping method of the characteristic subspace beams may be indicated by the network device, or predefined by the protocol, or the network device may indicate that a grouping method is selected from multiple grouping methods predefined by the protocol. After the network device indicates X, the terminal device may group the characteristic subspace beams according to the grouping method indicated by the network device or predefined by the protocol. The grouping method may be: for example, when X=2, it may be continuous grouping, with the first [N / 2] characteristic beams as one group and the last N-[N / 2] characteristic beams as another group, that is, N1=[N / 2], N2=N-[N / 2]. It may also be grouped according to the odd and even numbers of the characteristic subspace beams, with odd numbers as one group and even numbers as another group. The number of characteristic subspace beams is N.

[0160] Furthermore, the method may also include the following steps (this step is optional and is indicated by a dotted line in the figure):

[0161] S903. The UE sends fourth indication information to the network device. Correspondingly, the network device receives the fourth indication information.

[0162] The fourth indication information is used to indicate the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, N i is the number of beams in each set of characteristic subspace beams.

[0163] The above method is further described below by an example. In this example, there are N characteristic subspace beams, the dimension of each beam in the N beams is Q, and the statistical characteristic subspace beams are represented by a matrix B. The network device configures K basis vectors for the UE, using the matrix Indicates. The dimension of each basis vector in the K basis vectors is Q. The UE divides the N characteristic subspace beams into X groups (X=1 or X>1), and for each group of characteristic subspace beams, selects M basis vectors from the K basis vectors for the projection quantization of the group of characteristic subspace beams. The M basis vectors selected by the UE for each group of characteristic subspace beams can be completely different, partially the same, or completely the same. Among them, Fig.10 As shown, it is a schematic diagram of statistical feature subspace beam projection quantization in the case of X>1 in an example of an embodiment of the present application, where X>1 indicates that N feature subspace beams are divided into X groups, and for each group of feature subspace beams, M basis vectors are selected from K basis vectors to perform projection quantization on the group of feature subspace beams; Fig.11 As shown, it is a schematic diagram of statistical characteristic subspace beam projection quantization in the case of X=1 in an example of an embodiment of the present application. X=1 means that N characteristic subspace beams do not need to be grouped, and M basis vectors are selected from K basis vectors to perform projection quantization on the N characteristic subspace beams.

[0164] exist Fig.10 In the above example, N characteristic subspace beams are divided into X groups. The dimension of each beam in each group of characteristic subspace beams is Q. Each group of characteristic subspace beams includes N i The number of beams included in each set of characteristic subspace beams in the X sets of characteristic subspace beams can be the same or different. Each set of characteristic subspace beams is represented by the matrix For each set of characteristic subspace beams, the UE selects M basis vectors from the K basis vectors for the projection quantization of the set of characteristic subspace beams. Each set of basis vectors includes M basis vectors, and the M basis vectors belong to K basis vectors, M≤K. The dimension of the combination coefficient corresponding to each set of basis vectors in the X sets of basis vectors is M*N i In this case, the long-term reporting volume is In addition, as a special case, when X = N, each characteristic subspace beam selects M basis vectors from K basis vectors for projection quantization, and the long-term reporting amount is Bit.

[0165] exist Fig.11 In the above example, the N characteristic subspace beams do not need to be grouped and projected quantized using the same set of basis vectors. The UE selects M basis vectors from the K basis vectors to represent the N characteristic subspace beams. The selected set of basis vectors includes M basis vectors, which can be represented by the matrix Indicated by. The dimension of each basis vector in the M basis vectors is Q. The dimension of the combination coefficient corresponding to this group of basis vectors is M*N (using the matrix C 13 In this case, the long-term reporting amount is Bit.

[0166] According to a channel state information feedback method provided by an embodiment of the present application, a network device sends a basis vector configuration of a characteristic subspace beam to a terminal device; and the terminal device sends indication information of X groups of basis vectors selected by the terminal device from the basis vectors of the characteristic subspace beam to the network device according to the configuration, and the X groups of basis vectors are respectively used to characterize the X groups of characteristic subspace beams, and each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam. The indication information is used to indicate K basis vectors, and each group of basis vectors in the X groups of basis vectors includes M basis vectors, and the M basis vectors belong to K basis vectors, and M≤K. Since the number of basis vectors K in the basis vectors configured by the network device is greater than the number M actually used by the UE, that is, the network device configures more basis vectors (but K is less than the number of basis vectors in the full set), a certain selection space is given to the UE, and a compromise between reporting overhead and feedback accuracy can be achieved.

[0167] It can be understood that in the above embodiments, the methods and / or steps implemented by the UE can also be implemented by components that can be used for the UE (such as chips or circuits); the methods and / or steps implemented by the network device can also be implemented by components that can be used for the network device (such as chips or circuits).

[0168] The above mainly introduces the scheme provided by the embodiment of the present application from the perspective of interaction between various nodes. Accordingly, the embodiment of the present application also provides a communication device, which is used to implement the above various methods. The communication device can be a UE in the above method embodiment, or a component that can be used for a UE; or, the communication device can be a network device in the above method embodiment, or a component that can be used for a network device. It can be understood that in order to implement the above functions, the communication device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0169] The embodiment of the present application can divide the functional modules of the communication device according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0170] Based on the same concept of the above-mentioned channel state information feedback method, the present application also provides the following communication device:

[0171] like Fig.12 , which is a schematic diagram of the structure of a communication device provided in an embodiment of the present application, the communication device 1200 includes a transceiver unit 1201 and a processing unit 1202; wherein:

[0172] When the communication device is used to implement the function of the UE in the above method embodiment, the transceiver unit 1201 is used to execute the following steps: Figure 6 The operation of the UE in S601 to S603 in the embodiment shown; or, the transceiver unit 1201 is used to perform the following Fig. 9 The operations of the UE in S901 to S903 in the illustrated embodiment.

[0173] When the communication device is used to implement the function of the network device in the above method embodiment, the transceiver unit 1201 is used to execute the following steps: Figure 6 The operation of the network device in S601 to S603 in the embodiment shown; or, the transceiver unit 1201 is used to perform the following Fig. 9 The operation of the network device in S901 to S903 in the embodiment shown. For example, the transceiver unit 1201 can be deployed in Figure 2A , Figure 2B The processing unit 1202 can be deployed on the DU or RU in Figure 2A , Figure 2B or the functional part of the processing unit 1202 is deployed on Figure 2A , Figure 2B For example, the transceiver unit 1201 and the processing unit 1202 can be deployed on the DU and partly on the CU. Figure 2D For the specific implementation of the above transceiver unit 1201 and the processing unit 1202, reference may be made to the description in the above method embodiment.

[0174] like Fig.13 As shown, it is a schematic diagram of the structure of another communication device provided in an embodiment of the present application, and the communication device 1300 includes one or more processors 1301 (one processor is illustrated in the figure). Optionally, the communication device 1300 may also include a memory 1303 (indicated by a dotted line in the figure). The memory 1303 is used to store instructions executed by the processor 1301, or to store input data required for the processor 1301 to run instructions, or to store data generated after the processor 1301 runs instructions. Optionally, the communication device 1300 may also include an interface circuit 1302 (indicated by a dotted line in the figure), and the processor 1301 and the interface circuit 1302 are coupled to each other. It can be understood that the interface circuit 1302 can be a transceiver or an input-output interface. Among them, the processor 1301 is used to implement the above Fig.12 The functions of the processing unit 1202 in the embodiment shown; and the interface circuit 1302 are used to implement the above Fig.12 The functions of the transceiver unit 1201 in the illustrated embodiment.

[0175] When the above communication device is a chip applied to UE, the chip implements the functions of the UE in the above method embodiment. The chip receives information from other modules in the UE (such as a radio frequency module or an antenna), and the information is sent by the network device to the UE; or the chip sends information to other modules in the UE (such as a radio frequency module or an antenna), and the information is sent by the UE to the network device.

[0176] When the above communication device is a chip applied to a network device, the chip implements the functions of the network device in the above method embodiment. The chip receives information from other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the UE to the network device; or the chip sends information to other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the network device to the UE.

[0177] In addition, it should be noted that the aforementioned transceiver unit and / or processing unit can be implemented through a virtual module, for example, the processing unit can be implemented through a software function unit or a virtual device, and the transceiver unit can be implemented through a software function or a virtual device. Alternatively, the processing unit or the transceiver unit can also be implemented through a physical device, for example, if the device is implemented using a chip / chip circuit, the transceiver unit can be an input-output circuit and / or a communication interface, performing input operations (corresponding to the aforementioned receiving operations) and output operations (corresponding to the aforementioned sending operations); the processing unit is an integrated processor or microprocessor or integrated circuit.

[0178] The division of modules in this application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each example of this application may be integrated into one processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0179] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0180] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed, the method in the above embodiment is implemented.

[0181] The embodiments of the present application also provide a computer program product including instructions, which, when executed on a computer, enables the computer to execute the method in the above embodiments.

[0182] An embodiment of the present application also provides a communication system, including the above-mentioned communication device.

[0183] The embodiment of the present application also provides a circuit, which is coupled to a memory and is used to execute the method shown in the above embodiment. The circuit may include a chip circuit.

[0184] When the above-mentioned communication device is a module applied to a network device, the network device module implements the function of the network device in the above-mentioned method embodiment. The network device module receives information from other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the UE to the network device; or, the network device module sends information to other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the network device to the UE. The network device module here can be a baseband chip of a network device, or a CU, DU or other module, or a device under an open radio access network (open radio access network, O-RAN) architecture, such as an open CU, an open DU and other devices.

[0185] It should be noted that the above units or one or more of the units can be implemented by software, hardware or a combination of the two. When any of the above units or units is implemented by software, the software exists in the form of computer program instructions and is stored in a memory, and a processor can be used to execute the program instructions and implement the above method flow.

[0186] In this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or all or part of the circuits in the aforementioned devices for implementing processing functions, which may implement or execute the methods, steps and logic block diagrams disclosed in this application. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in this application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0187] When the above units or units are implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, a SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator or a non-integrated discrete device, which can run the necessary software or not rely on the software to execute the above method flow.

[0188] Optionally, the embodiment of the present application further provides a chip system, including: at least one processor and an interface, the at least one processor is coupled to a memory via the interface, and when the at least one processor runs a computer program or instruction in the memory, the chip system executes a method in any of the above method embodiments. Optionally, the chip system may be composed of a chip, or may include a chip and other discrete devices, which is not specifically limited in the embodiment of the present application.

[0189] The memory in the present application may also be a circuit or any other device capable of realizing a storage function, for storing program instructions and / or data. The memory is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. For example, the memory may be a non-volatile memory, such as a digital versatile disc (DVD), a hard disk drive (HDD) or a solid-state drive (SSD), etc., or a volatile memory (volatile memory), such as a random-access memory (RAM).

[0190] It should be understood that in the description of the present application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; wherein A and B can be singular or plural. Also, in the description of the present application, unless otherwise specified, "multiple" refers to two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, wherein a, b, c can be single or multiple. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art can understand that the words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not limit them to be necessarily different. Meanwhile, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0191] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center.

[0192] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0193] It is understood that the various numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

[0194] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0195] The components in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs. Those skilled in the art can combine or combine the different embodiments and features of the different embodiments described in this specification.

[0196] In the present application, under the premise of no logical contradiction, the examples may reference each other, for example, the methods and / or terms between method embodiments may reference each other, for example, the functions and / or terms between device embodiments may reference each other, for example, the functions and / or terms between device examples and method examples may reference each other.

Claims

1. A channel state information feedback method, characterized in that: The method comprises: Receive first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and P and M are positive integers greater than or equal to 1; Sending second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1.

2. The method according to claim 1, characterized in that The first indication information includes an index of the P group of basis vectors, or the first indication information includes the P group of basis vectors.

3. The method according to claim 1 or 2, characterized in that The method further comprises: Receive third indication information, where the third indication information is used to indicate the X.

4. The method according to any one of claims 1 to 3, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: Send fourth indication information, wherein the fourth indication information is used to indicate the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

6. A channel state information feedback method, characterized in that: The method comprises: Sending first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and P and M are positive integers greater than or equal to 1; Second indication information is received, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1.

7. The method according to claim 6, characterized in that The first indication information includes an index of the P group of basis vectors, or the first indication information includes the P group of basis vectors.

8. The method according to claim 6 or 7, characterized in that The method further comprises: Send third indication information, wherein the third indication information is used to indicate the X.

9. The method according to any one of claims 6 to 8, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

10. The method according to any one of claims 6 to 9, characterized in that The method further comprises: Receive fourth indication information, wherein the fourth indication information is used to indicate the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficients corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

11. A channel state information feedback method, characterized in that: The method comprises: Receive first indication information, where the first indication information is used to indicate K basis vectors, where K is a positive integer greater than or equal to 1; Sending second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, each group of basis vectors in the X groups of basis vectors includes M basis vectors, the M basis vectors belong to the K basis vectors, the M≤K, the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam.

12. The method according to claim 11, characterized in that The first indication information includes indices of the K basis vectors, or the first indication information includes the K basis vectors.

13. The method according to claim 11 or 12, characterized in that: The method further comprises: Receive third indication information, where the third indication information is used to indicate the X.

14. The method according to any one of claims 11 to 13, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

15. The method according to any one of claims 11 to 14, characterized in that The method further comprises: Send fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

16. A channel state information feedback method, characterized in that: The method comprises: Sending first indication information, wherein the first indication information is used to indicate K basis vectors, where K is a positive integer greater than or equal to 1; According to the first indication information, second indication information is received, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, each group of basis vectors in the X groups of basis vectors includes M basis vectors, the M basis vectors belong to the K basis vectors, the M≤K, the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam.

17. The method according to claim 16, characterized in that The first indication information includes indices of the K basis vectors, or the first indication information includes the K basis vectors.

18. The method according to claim 16 or 17, characterized in that The method further comprises: Send third indication information, wherein the third indication information is used to indicate the X.

19. The method according to any one of claims 16 to 18, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

20. The method according to any one of claims 16 to 19, characterized in that The method further comprises: Receive fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

21. A communication device, characterized in that: The device comprises: a transceiver unit; wherein: The transceiver unit is used to receive first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and P and M are positive integers greater than or equal to 1; The transceiver unit is further used to send second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1.

22. The device according to claim 21, characterized in that The first indication information includes an index of the P group of basis vectors, or the first indication information includes the P group of basis vectors.

23. The device according to claim 21 or 22, characterized in that The transceiver unit is further used to receive third indication information, wherein the third indication information is used to indicate the X.

24. The device according to any one of claims 21 to 23, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

25. The device according to any one of claims 21 to 24, characterized in that The transceiver unit is further used to send fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

26. A communication device, characterized in that: The device comprises: a transceiver unit; wherein: The transceiver unit is used to send first indication information, wherein the first indication information is used to indicate P groups of basis vectors, each group of basis vectors in the P groups of basis vectors includes M basis vectors, and P and M are positive integers greater than or equal to 1; The transceiver unit is further used to receive second indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, the X groups of basis vectors belong to the P groups of basis vectors, each group of characteristic subspace beams in the X groups of characteristic subspace beams includes at least one beam, and X is a positive integer greater than or equal to 1.

27. The device according to claim 26, characterized in that The first indication information includes an index of the P group of basis vectors, or the first indication information includes the P group of basis vectors.

28. The device according to claim 26 or 27, characterized in that The transceiver unit is further used to send third indication information, wherein the third indication information is used to indicate the X.

29. The device according to any one of claims 26 to 28, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

30. The device according to any one of claims 26 to 29, characterized in that The transceiver unit is further used to receive fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, wherein the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

31. A communication device, characterized in that: The device comprises: a transceiver unit; wherein: The transceiver unit is used to receive first indication information, wherein the first indication information is used to indicate K basis vectors, and K is a positive integer greater than or equal to 1; The transceiver unit is further used to send second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, each group of basis vectors in the X groups of basis vectors includes M basis vectors, the M basis vectors belong to the K basis vectors, the M≤K, the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam.

32. The device according to claim 31, characterized in that The first indication information includes indices of the K basis vectors, or the first indication information includes the K basis vectors.

33. The device according to claim 31 or 32, characterized in that The transceiver unit is further used to receive third indication information, wherein the third indication information is used to indicate the X.

34. The device according to any one of claims 31 to 33, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

35. The device according to any one of claims 31 to 34, characterized in that The transceiver unit is further used to send fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

36. A communication device, characterized in that: The device comprises: a transceiver unit; wherein: The transceiver unit is used to send first indication information, wherein the first indication information is used to indicate K basis vectors, and K is a positive integer greater than or equal to 1; The transceiver unit is further used to receive second indication information according to the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, the X groups of basis vectors are respectively used to characterize X groups of characteristic subspace beams, each group of basis vectors in the X groups of basis vectors includes M basis vectors, the M basis vectors belong to the K basis vectors, the M≤K, the X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam.

37. The device according to claim 36, characterized in that The first indication information includes indices of the K basis vectors, or the first indication information includes the K basis vectors.

38. The device according to claim 36 or 37, characterized in that The transceiver unit is further used to send third indication information, wherein the third indication information is used to indicate the X.

39. The device according to any one of claims 36 to 38, characterized in that When X=1, the second indication information is bit; when X>1, the second indication information is Bit.

40. The device according to any one of claims 36 to 39, characterized in that The transceiver unit is further used to receive fourth indication information, wherein the fourth indication information is used to indicate the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors, and the dimension of the combination coefficient corresponding to each group of basis vectors in the X groups of basis vectors is M*N i , where 1≤i≤X, the N i is the number of beams in each set of characteristic subspace beams.

41. A communication system, characterized in that: The system comprises a first communication device and a second communication device, the first communication device being used to implement the method according to any one of claims 1 to 5, and the second communication device being used to implement the method according to any one of claims 6 to 10.

42. A communication system, characterized in that: The system comprises a first communication device and a second communication device, the first communication device being used to implement the method according to any one of claims 11-15, and the second communication device being used to implement the method according to any one of claims 16-20.

43. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method as described in any one of claims 1-20 through a logic circuit or executing code instructions.

44. The communication device according to claim 43, characterized in that The communication device is a chip.

45. A chip module, characterized in that: The invention comprises a transceiver component and a chip, wherein the chip is used to execute the method as claimed in any one of claims 1 to 20.

46. ​​A computer-readable storage medium, characterized in that The storage medium stores a computer program or an instruction. When the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 20 is implemented.

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