Channel state information feedback method and related product

Abstract

A channel state information feedback method and a related product. The method comprises: a network device sending first indication information; and a terminal device sending second indication information on the basis of the first indication information, wherein the second indication information is used for indicating X groups of base vectors. The first indication information is used for indicating P groups of base vectors, and the X groups of base vectors belong to the P groups of base vectors, such that it is only necessary to select, from finite base vector groups, a base vector for representing a feature subspace beam, thereby reducing indication overheads of the base vector for representing the feature subspace beam, and also reducing the processing complexity; or the first indication information is used for indicating K base vectors, K being a positive integer greater than or equal to 1, and each group of base vectors among the X groups of base vectors comprises M base vectors, the M base vectors belonging to the K base vectors, and M being less than or equal to K, such that since the network device configures more base vectors, a certain selection space is provided for the terminal device, which makes it possible to realize a compromise between reporting overheads and feedback precision.

Description

Channel state information feedback method and related products

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 27, 2023, with application number 202311283936.5 and invention name “Channel State Information Feedback Method and Related Products”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] 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

[0003] The fifth generation (5 th 5G (5th generation) mobile communication systems have higher requirements for system capacity and spectrum efficiency. In 5G mobile communication systems, the application of massive multi-antenna technology plays a crucial role in improving the system's spectrum efficiency. When using multiple-input multiple-output (MIMO) technology, the base station needs to precode the data before sending it to the terminal device. The precoding method relies on the channel state information (CSI) fed back by the terminal device to the base station. Therefore, accurate CSI feedback is a key factor affecting system performance.

[0004] In frequency division duplex (FDD) mode, the frequency band separation between the uplink and downlink channels is much larger than the coherence bandwidth, resulting in a lack of complete reciprocity. This requires the user equipment to provide feedback on the downlink channel CSI to the base station. The base station then determines the precoding for data transmission based on the precoding matrix indicator (PMI) provided by the user equipment.

[0005] PMI feedback is determined and reported based on a codebook. The design of the FDD CSI codebook is a fundamental and important issue in 5G mobile communication systems. A codebook based on statistical characteristic subspaces has been proposed. This codebook is represented by a linear combination of characteristic subspace beams in the spatial and frequency domains. For this type of codebook, the terminal device needs to feedback the statistical characteristic subspace beams over a long period and the beam superposition coefficients over a short period. Directly feeding back the elements of the long-period statistical characteristic subspace beams results in high feedback overhead. Therefore, reducing the feedback overhead of characteristic subspace beams is a key issue for this type of codebook.

[0006] Summary of the Invention

[0007] The present application provides a channel state information feedback method and related products to reduce the overhead of feedback characteristic subspace beams.

[0008] In a first aspect, a channel state information feedback method is provided, which is performed by a terminal device or a chip or circuit for the 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 P and M are positive integers greater than or equal to 1; and sending second indication information based on the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, each of the X groups of basis vectors is used to represent 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. Using this method, the terminal device only needs to select basis vectors for representing characteristic subspace beams from a limited group of basis vectors, thereby reducing the basis vector indication overhead for representing characteristic subspace beams and reducing the processing complexity of the terminal device.

[0009] 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).

[0010] In one possible implementation, 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, or the protocol predefines a complete set of Q-dimensional basis vectors, and uses a bitmap or 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 may indicate 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 based on the index of the P group of basis vectors.

[0011] 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 may indicate the selection of 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 forming one group and the last N-[N / 2] characteristic beams forming another group, i.e., 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 forming one group and even numbers forming another group. The number of characteristic subspace beams is N, and [.] indicates rounding up or down.

[0012] 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.

[0013] Exemplarily, the first message and the second message may be the same message, or different messages.

[0014] 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 representing the characteristic subspace beam from a limited group of basis vectors, which reduces the basis vector indication overhead for representing the characteristic subspace beam and reduces the processing complexity of the terminal device.

[0015] 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 set of characteristic subspace beams. With this implementation, the terminal device also feeds back the combination coefficients corresponding to each of the X sets of basis vectors. This allows the network device to restore the characteristic subspace beams based on the X sets of basis vectors and the combination coefficients corresponding to each of the X sets of basis vectors fed back by the terminal device. The network device can then determine a precoding matrix based on the characteristic subspace beams and perform downlink data transmission based on the precoding matrix.

[0016] In a second aspect, a channel state information feedback method is provided, which is performed by a network device or a chip or circuit for the 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, where P and M are positive integers greater than or equal to 1; and receiving second indication information based on the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, each of which is used to represent X groups of characteristic subspace beams, the X groups of basis vectors belonging 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, where 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 basis vectors used to represent the characteristic subspace beams from a limited set of basis vectors, thereby reducing the basis vector indication overhead used to represent the characteristic subspace beams and reducing the processing complexity of the terminal device.

[0017] 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.

[0018] 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 the 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.

[0019] In another possible implementation, the method further includes: sending third indication information, wherein the third indication information is used to indicate the X.

[0020] 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.

[0021] Exemplarily, the first message and the second message may be the same message, or different messages.

[0022] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is bit.

[0023] 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.

[0024] 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, where K is a positive integer greater than or equal to 1; and sending second indication information based on the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, where the X groups of basis vectors are respectively used to represent 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, M ≤ K, X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam. Using this method, since the network device configures more basis vectors (but K is less than the number of basis vectors in the entire basis vector set), the UE is given a certain amount of selection space, which can achieve a compromise between reporting overhead and feedback accuracy.

[0025] 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.

[0026] 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 the 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.

[0027] 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 can be indicated by the network device, or predefined by the protocol, or the network device instructs the terminal device to select a grouping method from multiple grouping methods predefined by the protocol. After the network device indicates X, the terminal device can group the characteristic subspace beams according to the grouping method indicated by the network device or predefined by the protocol. The grouping method can be: for example, when X=2, it can be continuous grouping, with the first [N / 2] characteristic beams forming one group and the last N-[N / 2] characteristic beams forming another group, that is, N1=[N / 2], N2=N-[N / 2]. It can also be grouping according to the odd and even numbers of the characteristic subspace beams, with odd-numbered beams forming one group and even-numbered beams forming another group. The number of characteristic subspace beams is N.

[0028] 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.

[0029] Exemplarily, the first message and the second message may be the same message, or different messages.

[0030] 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 selects M from K basis vectors, where K is smaller than the number of basis vectors in the entire basis vector set. This gives the UE a certain amount of selection space, and can achieve a compromise between reporting overhead and feedback accuracy.

[0031] 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 set of characteristic subspace beams. With this implementation, the terminal device also feeds back the combination coefficients corresponding to each of the X sets of basis vectors. This allows the network device to restore the characteristic subspace beams based on the X sets of basis vectors and the combination coefficients corresponding to each of the X sets of basis vectors fed back by the terminal device. The network device can then determine a precoding matrix based on the characteristic subspace beams and perform downlink data transmission based on the precoding matrix.

[0032] 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 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; and receiving second indication information based on the first indication information, wherein the second indication information is used to indicate X groups of basis vectors, where the X groups of basis vectors are respectively used to represent 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, M≤K, X is a positive integer greater than or equal to 1, and each group of characteristic subspace beams includes at least one beam. Using this method, since the network device configures more basis vectors (but K is less than the number of basis vectors in the entire basis vector set), the UE is given a certain amount of selection space, which can achieve a compromise between reporting overhead and feedback accuracy.

[0033] 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.

[0034] 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 the 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.

[0035] In another possible implementation, the method further includes: sending third indication information, wherein the third indication information is used to indicate the X.

[0036] 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.

[0037] Exemplarily, the first message and the second message may be the same message, or different messages.

[0038] In another possible implementation, when X=1, the second indication information is bit; when X>1, the second indication information is bit.

[0039] 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.

[0040] The methods of the first and third aspects above can be executed by a terminal device, or by a module applied to the terminal 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 terminal device functions.

[0041] The methods of the second and fourth aspects 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.

[0042] In a fifth aspect, a communication device is provided, configured to implement the channel state information feedback method of the first aspect or any one of its implementations; or configured to implement the channel state information feedback method of the third aspect or any one of its implementations. The device may be a terminal device, a module (such as a processor, chip, or chip system) applied to the terminal device, or a logical node, logical module, or software capable of implementing all or part of the functions of the terminal device.

[0043] In a sixth aspect, a communication device is provided, configured to implement the channel state information feedback method of the second aspect or any one of its implementations; or configured to implement the channel state information feedback method of the fourth aspect or any one of its implementations. The device may be a network device, a module (such as a processor, chip, or chip system) applied to a network device, or a logical node, logical module, or software capable of implementing all or part of the network device's functions.

[0044] In one possible implementation, the communication device of the fifth to sixth aspects includes a module for respectively executing the method of any one of the first to fourth aspects or any one of their implementations. Exemplarily, the communication device may include a transmitting unit, a receiving unit, and a processing unit. The transmitting unit and the receiving unit may be independent or combined (referred to as a "transceiver unit").

[0045] 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 enable the device to perform the corresponding functions in the channel state information feedback method. The memory is coupled to the processor and stores the necessary programs (instructions) and / or data for the device. Optionally, the communication device may further include a communication interface for enabling communication between the device and other network elements. Optionally, the memory may be located inside or outside the communication device.

[0046] In another possible implementation, the communication device in the fifth to sixth aspects includes a processor and a transceiver, the processor being coupled to the transceiver, and the processor being 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 execution code instruction. The transceiver may be a transceiver, a transceiver circuit, an interface circuit, or an input / output interface, configured to receive signals from other communication devices other than the communication device and transmit them to the processor, or to send signals from the processor to other communication devices other than the communication device. When the communication device is a chip, the transceiver is a transceiver circuit or an input / output interface.

[0047] When the communication device in the fifth and sixth aspects above is a chip, the sending unit may be an output unit, such as an output circuit or a communication interface; and 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; and the receiving unit may be a receiver or a receiver.

[0048] 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.

[0049] In an eighth aspect, a chip is provided, wherein the chip is used to execute the methods described in the above aspects.

[0050] In a ninth aspect, a chip module is provided, comprising a transceiver component and a chip, wherein the chip is used to execute the methods described in the above aspects.

[0051] 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. When the computer program or instruction is executed, the methods described in the above aspects are implemented.

[0052] In an eleventh aspect, a computer program product comprising instructions is provided, which, when the instructions are executed on a communication device, causes the communication device to execute the methods described in the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG1 is a simplified schematic diagram of a wireless communication system provided by an embodiment of the present application;

[0054] 2A to 2D are schematic diagrams of network architectures provided in embodiments of the present application;

[0055] FIG3 is a schematic diagram of the basic process of network equipment and UE obtaining CSI;

[0056] FIG4 is a schematic diagram of a spatial-frequency domain joint statistical feature subspace codebook structure;

[0057] FIG5 is a schematic diagram of statistical characteristic subspace beam projection quantization;

[0058] FIG6 is a flow chart of a channel state information feedback method provided in an embodiment of the present application;

[0059] FIG7 is a schematic diagram of statistical feature subspace beam projection quantization in a case where X>1 according to an embodiment of the present application;

[0060] FIG8 is a schematic diagram of statistical feature subspace beam projection quantization in a case where X=1 according to an embodiment of the present application;

[0061] FIG9 is a schematic diagram of a flow chart of another channel state information feedback method provided in an embodiment of the present application;

[0062] FIG10 is a schematic diagram of statistical feature subspace beam projection quantization in another case where X>1 according to an embodiment of the present application;

[0063] FIG11 is a schematic diagram of statistical feature subspace beam projection quantization in another case where X=1 according to an embodiment of the present application;

[0064] FIG12 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0065] FIG13 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0066] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0067] The following at least one (item) involved in this application 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 previous and next associated objects 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 this application, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0068] The terms "including" and "having" and any variations thereof mentioned in the following description of this 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 may optionally include other steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices. It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any method or design described in this application as "exemplary" or "for example" 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.

[0069] The technology provided by this application can be applied to various communication systems. For example, the communication system can be a fourth generation (4G) th generation (4G) mobile communication systems (such as long term evolution (LTE) systems), 5G mobile communication systems, worldwide interoperability for microwave access (WiMAX) or wireless local area network (WLAN) systems, or integrated systems of multiple systems, or future communication systems such as the sixth generation (6G) th generation, 6G) mobile communication system, etc. Among them, the 5G mobile communication system can also be called a new radio (NR) system.

[0070] 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 can also be replaced by an entity, a network entity, a device, a terminal device, a communication module, a node, a communication node, etc. The present application uses the network element as an example for description. For example, the communication system may include at least one terminal device and at least one access network device. The access network device can send a downlink signal to the terminal device, and / or the terminal device can send an uplink signal to the access network device. In addition, it can be understood that if the communication system includes multiple terminal devices, the multiple terminal devices can also send signals to each other, that is, the signal sending network element and the signal receiving network element can both be terminal devices.

[0071] Refer to Figure 1, which is a simplified schematic diagram of a wireless communication system provided in an embodiment of the present application. As shown in Figure 1, the wireless communication system includes a wireless access network 100. The wireless access network 100 can 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) can be connected to each other, or connected to one or more network devices (110a, 110b, collectively referred to as 110) in the wireless access network 100. Optionally, Figure 1 is only a schematic diagram, and the wireless communication system may also include other devices, such as core network devices, wireless relay devices and / or wireless backhaul devices, which are not shown in Figure 1.

[0072] Optionally, in actual applications, the wireless communication system may include multiple network devices (also called access network devices) and multiple terminal devices at the same time. A network device can serve one or more terminal devices at the same time. A terminal device can also access one or more network devices at the same time. The embodiments of the present application do not limit the number of terminal devices and network devices included in the wireless communication system.

[0073] 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 various names as follows, or be replaced with the following names, such as: radio access network (RAN) node, NodeB, evolved NodeB (eNB), next generation NodeB (gNB), access network equipment in open radio access network (O-RAN), relay station, access point, transmission point (TRP), 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, building baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), distributed unit (DRU), etc. The network device may also refer to a mobile switching center and a device that performs base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. 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.

[0074] Network devices can be fixed or mobile. For example, base stations 110a and 110b are stationary and are responsible for wireless transmission and reception in one or more cells from terminal device 120. The helicopter or drone 120i shown in Figure 1 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 base station 110b.

[0075] In this application, the communication device used to implement the above-mentioned access network function can be an access network device, a network device having some of the access network functions, 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 and a software module. The device can be installed in the access network device or used in combination with the access network device. In the method of this application, the communication device used to implement the access network device function is described as an access network device.

[0076] A terminal device may be an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal device may be used to connect people, objects, and machines. The terminal device may communicate with one or more core networks through a network device. The terminal device includes a handheld device with wireless connection capabilities, other processing devices connected to a wireless modem, or a vehicle-mounted device. The terminal device may be a portable, pocket-sized, handheld, computer-built-in, or vehicle-mounted mobile device. The terminal device 120 may 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 wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.Some examples of the terminal device 120 include: user equipment (UE) of the 3GPP standard, fixed equipment, mobile equipment, handheld equipment, wearable equipment, cellular phones, smart phones, session initiated protocol (SIP) phones, laptops, personal computers, smart books, vehicles, satellites, global positioning system (GPS) equipment, target tracking equipment, drones, helicopters, aircraft, ships, remote control equipment, smart home equipment, industrial equipment, personal communication service (PCS) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), wireless network cameras, tablet computers, handheld computers, 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 the above various scenarios or a device for being set up 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.

[0077] Alternatively, a terminal device can function as a base station. For example, a UE can act as a dispatching entity, providing sidelink signals between UEs in V2X, D2D, or P2P scenarios. As shown in Figure 1, a cell phone 120a and a car 120b communicate with each other using sidelink signals. Cell phone 120a and smart home device 120e communicate without relaying the communication signals through base station 110b.

[0078] In this application, the communication device used to implement the functions of the terminal device can be a terminal device, or a terminal device with some of the functions of the above terminal devices, or a device that can support the implementation of the functions of the above terminal devices, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device. In this application, the chip system can be composed of chips, or it can include chips and other discrete devices. In the technical solution provided in this application, the communication device is described as a terminal device or UE as an example.

[0079] Optionally, a wireless communication system is typically composed of cells, with base stations providing cell management and 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 locations, for example: the RRU is remote and placed in an area with high traffic volume, while 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 the same rack. Optionally, a cell can correspond to a carrier or component carrier.

[0080] In some deployments, the network devices mentioned in the embodiments of the present application may include a CU, a DU, or both a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)), a user plane CU node (central unit-user plane (CU-UP)), and a DU node. For example, the network devices may include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0081] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of the base station's functionality. For example, a RAN node can be a CU, DU, CU-CP, CU-UP, or RU. The CU and DU can be separate or included in the same network element, such as the BBU. The RU can be included in a radio frequency device or radio unit, such as an RRU, AAU, or RRH.

[0082] The RAN node may support one or more types of fronthaul interfaces, with different fronthaul interfaces corresponding 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 type of interface, relative to the CPRI, some of the downlink and / or uplink baseband functions, such as precoding, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix (CP) for downlink, 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) / cyclic prefix (CP) removal, are moved from the DU to the RU for implementation. In one possible implementation, the interface may be an enhanced common public radio interface (eCPRI). In the eCPRI architecture, the division between the DU and RU is different, corresponding to different types (category, Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, and F.

[0083] 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 preceding it (i.e., one or more of coding, rate matching, scrambling, modulation, and layer mapping). Other functions after layer mapping (e.g., RE mapping, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix (CP) addition) are moved to the RU for implementation. For uplink transmission, based on RE demapping, the DU is configured to implement demapping and one or more functions preceding it (i.e., one or more of decoding, rate matching, descrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and RE demapping). Other functions after demapping (e.g., one or more of digital BF or fast Fourier transform (FFT) / CP removal) are moved to the RU for implementation. It is understandable that for the functional description of DU and RU corresponding to various types of eCPRI, reference can be made to the eCPRI protocol, which will not be described in detail here.

[0084] In one possible design, the processing unit for implementing baseband functions in the BBU is called a baseband high layer (BBH) unit, and the processing unit for implementing baseband functions in the RRU / AAU / RRH is called a baseband low layer (BBL) unit.

[0085] 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 of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0086] In the embodiments of the present application, the device for implementing the functions of the network device can be a network device; it can also be a device that can support the network device to implement the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit and a software module. The device can be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the device for implementing the functions of the network device is used as an example to illustrate, and does not constitute a limitation on the solutions of the embodiments of the present application.

[0087] It is understandable that the present application can be applied between network devices and terminal devices.

[0088] 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 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 PDCP layer, the RLC layer, the MAC layer, and the physical layer. In one possible implementation, a service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0089] Optionally, the protocol layer structure between the network device and the terminal device may further include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0090] Taking data transmission between network devices and terminal devices as an example, data transmission needs to pass through the user plane protocol layers, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. The SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer can also be collectively referred to as the access layer. Data transmission is divided into sending or receiving based on the direction of transmission, and each of these layers is further 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 MAC layer. The MAC layer then generates a transport block, which is then wirelessly transmitted through the physical layer. Data is encapsulated accordingly in each layer. For example, data received by a layer from the layer above it is considered a service data unit (SDU) of that layer. After encapsulation by that layer, it becomes a protocol data unit (PDU) and is then passed to the next layer.

[0091] For example, a terminal device may also include an application layer and a non-access layer. The application layer can be used to provide services to applications installed in the terminal device. For example, downlink data received by the terminal device can be sequentially transmitted from the physical layer to the application layer, which then provides it to the application. For another example, the application layer can obtain data generated by the application and sequentially transmit the data to the physical layer for transmission to other communication devices. The non-access layer can 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.

[0092] In order to support AI technology in wireless networks, AI nodes may also be introduced into the network.

[0093] 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. Alternatively, the AI ​​node can be deployed separately, for example, 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, such as one or more of the following: network equipment, terminal equipment, or network elements of the core network.

[0094] It is understood that this 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 function, such as different AI nodes are responsible for different functions.

[0095] 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.

[0096] An AI node can be an AI network element or an AI module.

[0097] One or more AI modules are provided in one or more of these network element nodes, such as core network equipment, access network nodes (RAN nodes), terminals or OAM devices. 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.

[0098] 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 bias in the activation function), input parameters (such as the type of input parameters and / or the dimension of the input parameters), or output parameters (such as the type of output parameters and / or the dimension of the output parameters). Among them, the bias in the activation function can also be called the bias of the neural network.

[0099] An AI module can have one or more models. A model can infer an output, which includes one or more parameters. The learning, training, or inference processes of different models can be deployed on different nodes or devices, or on the same node or device.

[0100] The communication system includes a RAN intelligent controller (RIC). For example, the RIC can 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 can 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.

[0101] 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 network-side and / or terminal-side information from RAN nodes (e.g., 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 deliver 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 delivers the reasoning results to the DU, and the DU sends it to the RU.

[0102] Non-real-time RIC is also used for model training and reasoning. For example, it is used to train AI models and use the models for reasoning. Non-real-time RIC can obtain network-side and / or terminal-side information 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 terminal. Optionally, the reasoning results can be exchanged between the CU and DU, and / or between the DU and RU. For example, the non-real-time RIC submits the reasoning results to the DU, and the DU sends it to the RU.

[0103] The near-real-time RIC and non-real-time RIC can also be set up as separate network elements. Optionally, the near-real-time RIC and non-real-time RIC can also be part of other devices. For example, the near-real-time RIC is set up in a RAN node (e.g., a CU or DU), while the non-real-time RIC is set up in an OAM, a cloud server, a core network device, or other network devices.

[0104] For example, the configuration of near real-time RIC and non-real-time RIC in the network architecture may be as shown in FIG. 2A to FIG. 2D :

[0105] As shown in (a) of FIG. 2A , in a first possible implementation, the access network device includes a near real-time RIC module for performing model learning and / or reasoning.

[0106] As shown in (b) of FIG2A , 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.

[0107] As shown in (c) of Figure 2A, in a third possible implementation, the access network device includes a near real-time RIC, and a non-real-time RIC is also included outside the access network device. Optionally, the non-real-time RIC can be located in the OAM or core network device.

[0108] Compared to (c) in Figure 2A, the CU is separated into CU-CP and CU-UP in Figure 2B. The settings of near-real-time RIC and non-real-time RIC are the same as those in (c) in Figure 2A.

[0109] As shown in Figure 2C, 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 and / or weights of the model), input parameters of the model, or output parameters of the model.

[0110] Relative to Figure 2C, the access network device in Figure 2D is 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 CU in Figure 2D can be further 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, in Figure 2C or Figure 2D, the OAM of the access network device and the OAM of the core network device can be deployed separately and independently.

[0111] It should be understood that the number and type of each device in the communication system shown in Figure 1 are for illustration only, and the present application is not limited to this. 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.

[0112] 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 for implementing 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, since the terminal equipment and the access network equipment involve interfaces for air interface transmission, 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 for implementing artificial intelligence functions can be implemented by cloud devices, such as cloud devices in over the top (OTT) systems.

[0113] 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 period of time (the 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 reciprocity exists. Network equipment can use channel reciprocity to obtain the CSI of the downlink channel through the uplink channel, and then perform precoding.

[0114] In FDD mode, the frequency band spacing between the uplink and downlink channels is much larger than the coherence 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 device, as shown in Figure 3, a basic flow diagram of the network device and UE obtaining CSI. The process includes the following steps: S301. The network device sends channel measurement configuration information to the UE, notifying the UE of the time and behavior of the channel measurement; then, S302. The network device sends a channel measurement pilot to the UE for channel measurement; S303. The UE performs measurements based on 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 based on the CSI fed back by the UE. Among them, the network device determines the number of data streams to be transmitted to the UE based on the channel rank indicator (RI) fed back by the UE; the network device determines the modulation order and channel coding code rate of the data transmitted to the UE based on the channel quality indicator (CQI) fed back by the UE; and the network device determines the precoding of the data transmitted to the UE based on the PMI fed back by the UE.

[0115] 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. Currently, FDD CSI feedback uses information on the network device side as a reference for channel quantization. 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 release (Rel-) 15 Type II codebook adopts the idea of ​​spatial (angle) compression, representing the main eigenvector (i.e., the precoding matrix of a single user) as 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 utilizing the frequency domain correlation of the amplitude and phase coefficients of different subbands, and represents the main eigenvector as a bilinear combination of several spatial DFT basis vectors and several frequency domain DFT basis vectors. To fully utilize the sparsity of the channel in the space-frequency domain and further improve the accuracy of PMI feedback, a codebook based on statistical feature subspaces is proposed. This codebook uses a linear combination of long-period statistical feature subspace beams to approximate the downlink channel or the main eigenvector of the downlink channel. This codebook can be similar to the Rel-16 Type II codebook, where the space and frequency domains are each represented by a set of statistical feature subspace beams through a bilinear combination. It can also be represented by a linear combination of a set of space-frequency domain joint feature subspace beams, as shown in Figure 4. For this type of codebook, the UE needs to feedback the statistical feature subspace beams for a long period and the beam superposition coefficients for a short period. If scalar quantization is used to directly feedback the elements of the long-period feedback statistical feature subspace beam, the feedback overhead is large. How to feedback the long-period statistical feature subspace beam with low overhead is a key issue for this type of codebook.

[0116] To solve the long-period feedback problem of the statistical feature subspace beam, a projection quantization scheme is currently used. Each beam in the statistical feature subspace beam set is approximately represented by a linear combination of the same set of DFT basis vectors. The schematic diagram of the statistical feature subspace beam projection quantization is shown in Figure 5, where N t *N f Indicates 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.

[0117] However, due to the large dimension of the DFT basis vectors used to quantize the eigenbeams, 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 The M bits are used to indicate the M DFT basis vectors used for statistical eigenspace beam projection quantization. On the other hand, because all eigenbeams use the same set of basis vectors for projection, the eigenbeam projection quantization accuracy is limited, which in turn affects the overall accuracy of PMI feedback. The linear / bilinear combination of statistical eigenspace beams cannot well approximate the downlink channel or the main eigenvector.

[0118] The above solution does not fully consider the high feedback overhead caused by the large dimensions of the basis vectors used for eigenbeam projection quantization. A pressing challenge for this type of codebook based on statistical eigenbeams is how to leverage the partial reciprocity of FDD uplink and downlink channels to report statistical eigenbeams with minimal feedback overhead without sacrificing accuracy.

[0119] In view of this, the present application provides a communication solution in which a network device sends indication information of P groups of basis vectors to a terminal device; and the terminal device, based on the indication information, sends indication information of X groups of basis vectors within the P groups of basis vectors to the network device. The X groups of basis vectors are respectively used to represent X groups of characteristic subspace beams, and each group of characteristic subspace beams within the X groups of characteristic subspace beams includes at least one beam. As a result, the terminal device only needs to select basis vectors for representing characteristic subspace beams from a limited set of basis vectors, reducing the overhead of indicating the basis vectors used to represent the characteristic subspace beams and the processing complexity of the terminal device.

[0120] 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 being the UE. This 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 being 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, 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.

[0121] 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 diagram, but the present application does not limit the execution subject of the interaction diagram. For example, the UE in the method provided by the present application can 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 can 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 functions.

[0122] As shown in Figure 6, a flow chart of a channel state information feedback method provided in an embodiment of the present application is shown. Exemplarily, the method may include the following steps:

[0123] S601. A network device sends first indication information to a UE. Correspondingly, the UE receives the first indication information.

[0124] In FDD mode, the frequency band spacing of the uplink and downlink channels is much larger than the coherence bandwidth, and the uplink and downlink channels have partial reciprocity, such as angular 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 sets of basis vectors. In addition, this solution is based on a codebook of statistical characteristic subspaces, which uses a linear combination of long-period statistical characteristic subspace beams to approximate the main eigenvectors of the downlink channel. Therefore, in this embodiment, the network device configures one or more sets of basis vectors through signaling for the UE to select and project the quantized characteristic subspace beams.

[0125] 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 for a statistical characteristic subspace beam (hereinafter referred to as a "characteristic subspace beam"). Exemplarily, the first indication information is used to indicate P groups of basis vectors, where each group of basis vectors in the P groups includes M basis vectors, where P and M are positive integers greater than or equal to 1.

[0126] The first indication information is used to indicate P groups of basis vectors, and can be implemented in the following two ways:

[0127] In one implementation, the first indication information includes indices of P groups of basis vectors. The protocol predefines a Q-dimensional set of basis vectors (including Q basis vectors). Each group of basis vectors indicated by the network device via the first indication information is selected from the Q-dimensional set of basis vectors predefine by the protocol, and the indexes of the P groups of basis vectors are sufficient. For example, the basis vectors may be DFT basis vectors.

[0128] 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.

[0129] 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.

[0130] In another implementation, a protocol may predefine a complete set of Q-dimensional basis vectors, and use a bitmap or combination number to indicate which M basis vectors are selected from the Q basis vectors for each of the P groups of basis vectors.

[0131] In another example, the value of P may also be indicated by the UE through a UE capability parameter or predefined by a protocol.

[0132] 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.

[0133] After receiving the first indication information, the UE divides the characteristic subspace beams into X groups (X=1 or X>1) and selects X groups of basis vectors from the P groups of basis vectors for projective quantization of the 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 represent 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. The UE then sends 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.

[0134] 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 of the characteristic subspace beam. Exemplarily, the third indication information is used to indicate the aforementioned 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, and DCI. The second message and the aforementioned first message may be the same message, or different messages.

[0135] In another example, X may also be determined by the UE or predefined by a protocol.

[0136] 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 forming one group and the last N-[N / 2] characteristic beams forming another group, i.e., 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 forming one group and even numbers forming another group. The number of characteristic subspace beams is N.

[0137] After receiving the second indication information, the network device can reconstruct the downlink channel by combining the angle and delay information estimated through the uplink channel.

[0138] Furthermore, the method may further include the following steps (this step is optional and is indicated by a dotted line in the figure):

[0139] S603. The UE sends fourth indication information to the network device. Correspondingly, the network device receives the fourth indication information.

[0140] 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, N i is the number of beams in each set of characteristic subspace beams.

[0141] The above method is further described below by an example. In this example, there are N characteristic subspace beams, and the dimension of each beam in the N beams is Q. The statistical characteristic subspace beams are represented by a matrix B. Based on the uplink channel measurement results and 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, using the matrix Represents, where 1≤p≤P, and p is a positive integer. Each group of basis vectors in 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 basis vector in the M basis vectors is Q. The UE selects X groups (X=1 or N>1) in the P groups for the projection quantization of the N characteristic subspace beams. As shown in FIG7 , it is a schematic diagram of the statistical characteristic subspace beam projection quantization in the case of X>1 in an example of an embodiment of the present application, and X>1 indicates that the N characteristic subspace beams are divided into X groups, and each group of characteristic subspace beams selects a group of basis vectors from the P groups of basis vectors for projection quantization; as shown in FIG8 , it is a schematic diagram of the statistical characteristic subspace beam projection quantization in the case of X=1 in an example of an embodiment of the present application, and X=1 indicates that the N characteristic subspace beams do not need to be grouped, and a group of basis vectors are selected from the P groups of basis vectors for projection quantization.

[0142] In Figure 7, N eigenvalue subspace beams are divided into X groups. The dimension of each beam in each group of eigenvalue subspace beams is Q. Each group of eigenvalue subspace beams includes Ni beams. The number of beams included in each group of X groups of eigenvalue subspace beams can be the same or different. Each group of eigenvalue 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. 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 coefficient 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.

[0143] In Figure 8, N eigenspace beams do not need to be grouped and projected using the same set of basis vectors. 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, and the dimension of each basis vector in the M basis vectors is Q. The dimension of the combination coefficient 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 projective quantization of all eigensubspace beams.

[0144] 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, based on the indication information, sends indication information of X groups of basis vectors in the P groups of basis vectors to the network device. The X groups of basis vectors are respectively used to represent 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. As a result, the terminal device only needs to select basis vectors used to represent characteristic subspace beams from a limited group of basis vectors, reducing the basis vector indication overhead used to represent characteristic subspace beams and reducing the processing complexity of the terminal device.

[0145] 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 set of basis vectors. Compared with the embodiment shown in FIG5 , in which each beam in the statistical characteristic subspace beam set is approximately represented by a linear combination of the same set of basis vectors, the projection quantization accuracy of the characteristic beams is improved, thereby improving the overall feedback accuracy of the PMI.

[0146] However, due to the limited reciprocity of the uplink and downlink space-frequency parts, the basis vectors pre-configured by the network device may be different 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 information to the terminal device; and the terminal device sends a second indication information to the network device according to the first indication information, and the second indication information 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 information 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), giving the UE a certain amount of choice space, it is possible to achieve a compromise between reporting overhead and feedback accuracy.

[0147] FIG9 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:

[0148] S901. A network device sends first indication information to a UE. Correspondingly, the UE receives the first indication information.

[0149] In this embodiment, a network device configures multiple basis vectors through signaling for the UE to select and project a quantized characteristic subspace beam. Exemplarily, the network device sends first indication information to the UE. Exemplarily, the network device sends first indication information to the UE. The first indication information is used to indicate the basis vector configuration of the characteristic subspace beam. Exemplarily, the first indication information is used to indicate K basis vectors, where K is a positive integer greater than or equal to 1. Exemplarily, the basis vectors are DFT basis vectors.

[0150] The first indication information is used to indicate K basis vectors and can be implemented in the following two ways:

[0151] In one implementation, the first indication information includes indices 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 indices of the K basis vectors are sufficient.

[0152] 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 of the K basis vectors to the UE.

[0153] 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.

[0154] In yet another implementation, a protocol may predefine a full set of Q-dimensional basis vectors, and use a bitmap or combination number to indicate which K basis vectors to select from the Q basis vectors.

[0155] In another example, the value of K may also be indicated by the UE through a UE capability parameter or predefined by a protocol.

[0156] 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.

[0157] 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 projective quantization of the group of characteristic subspace beams, where M 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, 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, 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 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.

[0158] Exemplarily, the M basis vectors selected by the UE for each group of eigensubspace beams may be completely different, partially the same, or completely the same.

[0159] 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 of the characteristic subspace beam. Exemplarily, the third indication information is used to indicate the aforementioned 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, and DCI. Exemplarily, the second message and the aforementioned first message may be the same message, or different messages.

[0160] In another example, X may also be indicated by the UE or predefined by a protocol.

[0161] 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 forming one group and the last N-[N / 2] characteristic beams forming another group, i.e., 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 forming one group and even numbers forming another group. The number of characteristic subspace beams is N.

[0162] Furthermore, the method may further include the following steps (this step is optional and is indicated by a dotted line in the figure):

[0163] S903. The UE sends fourth indication information to the network device. Correspondingly, the network device receives the fourth indication information.

[0164] 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, N i is the number of beams in each set of characteristic subspace beams.

[0165] The following example further describes the above method. In this example, there are N characteristic subspace beams, and the dimension of each beam in the N beams is Q. The statistical characteristic subspace beams are represented by matrix B. The network device configures K basis vectors for the UE, using matrix Represents. 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 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. As shown in Figure 10, 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 the N characteristic subspace beams are divided into X groups, and for each group of characteristic subspace beams, M basis vectors are selected from the K basis vectors to perform projection quantization on the group of characteristic subspace beams; as shown in Figure 11, 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 the N characteristic subspace beams do not need to be grouped, and M basis vectors are selected from the K basis vectors to perform projection quantization on the N characteristic subspace beams.

[0166] In Figure 10, 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 in each of the X groups of characteristic subspace beams can be the same or different. Each group 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 projected 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, where 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.

[0167] In Figure 11, the N characteristic subspace beams do not need to be grouped and the same set of basis vectors are used for projection quantization. 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, and the M basis vectors 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.

[0168] 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 based on the configuration, wherein 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, 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, where 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, which can achieve a compromise between reporting overhead and feedback accuracy.

[0169] 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).

[0170] The above mainly introduces the solutions provided by the embodiments of the present application from the perspective of interaction between various nodes. Accordingly, the embodiments of the present application also provide a communication device, which is used to implement the various methods described above. The communication device can be the UE in the above method embodiments, or a component that can be used for the UE; alternatively, the communication device can be the network device in the above method embodiments, or a component that can be used for the network device. It is understood that in order to implement the above functions, the communication device includes hardware structures and / or software modules corresponding to performing each function. Those skilled in the art should readily appreciate that, in combination with the various exemplary units and algorithm steps described in the embodiments 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 implemented in hardware or in a hardware-driven manner by computer software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0171] In the embodiment of the present application, the functional modules of the communication device can be divided 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 modules 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 functional division. In actual implementation, there may be other division methods.

[0172] Based on the same concept of the above-mentioned channel state information feedback method, the present application also provides the following communication device:

[0173] As shown in FIG12 , a schematic diagram of the structure of a communication device provided in an embodiment of the present application is shown. The communication device 1200 includes a transceiver unit 1201 and a processing unit 1202 .

[0174] When the communication device is used to implement the functions of the UE in the above method embodiment, the transceiver unit 1201 is used to perform the operations of the UE in S601 to S603 in the embodiment shown in Figure 6; or, the transceiver unit 1201 is used to perform the operations of the UE in S901 to S903 in the embodiment shown in Figure 9.

[0175] When the communication device is used to implement the functions of the network device in the above method embodiment, the transceiver unit 1201 is used to perform the operations of the network device in S601 to S603 in the embodiment shown in Figure 6; or, the transceiver unit 1201 is used to perform the operations of the network device in S901 to S903 in the embodiment shown in Figure 9. For example, the transceiver unit 1201 can be deployed on the DU or RU in Figures 2A and 2B, and the processing unit 1202 can be deployed on the DU in Figures 2A and 2B; or the functional part of the processing unit 1202 is deployed on the DU in Figures 2A and 2B and partially deployed on the CU. For another example, both the transceiver unit 1201 and the processing unit 1202 can be deployed on the DU in Figure 2D. For the specific implementation of the above transceiver unit 1201 and the processing unit 1202, please refer to the description in the above method embodiment.

[0176] As shown in Figure 13, it is a structural diagram of another communication device provided in an embodiment of the present application, and the communication device 1300 includes one or more processors 1301 (an example processor is shown in the figure). Optionally, the communication device 1300 may further 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 the instructions, or to store data generated after the processor 1301 runs the instructions. Optionally, the communication device 1300 may further 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 will be understood that the interface circuit 1302 can be a transceiver or an input and output interface. Among them, the processor 1301 is used to implement the function of the processing unit 1202 in the embodiment shown in Figure 12 above; and the interface circuit 1302 is used to implement the function of the transceiver unit 1201 in the embodiment shown in Figure 12 above.

[0177] When the communication device is a chip used in a UE, the chip implements the UE functions in the above method embodiments. The chip receives information from other modules in the UE (such as a radio frequency module or antenna), which is sent by a network device to the UE; or the chip sends information to other modules in the UE (such as a radio frequency module or antenna), which is sent by the UE to the network device.

[0178] When the communication device is a chip used in a network device, the chip implements the functions of the network device in the above method embodiments. The chip receives information from other modules in the network device (such as a radio frequency module or 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 antenna), and the information is sent by the network device to the UE.

[0179] In addition, it should be noted that the aforementioned transceiver unit and / or processing unit may be implemented through virtual modules, for example, the processing unit may be implemented through a software function unit or a virtual device, and the transceiver unit may be implemented through a software function or a virtual device. Alternatively, the processing unit or transceiver unit may also be implemented through a physical device, for example, if the device is implemented using a chip / chip circuit, the transceiver unit may 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 may be an integrated processor, microprocessor, or integrated circuit.

[0180] The division of modules in this application is illustrative and represents only a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the examples of this application may be integrated into a single processor, exist physically as separate modules, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in either hardware or software functional modules.

[0181] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be 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.

[0182] 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.

[0183] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the method in the above embodiment.

[0184] An embodiment of the present application also provides a communication system, including the above-mentioned communication device.

[0185] 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.

[0186] When the above-mentioned communication device is a module applied to a network device, the network device module implements the functions 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 the network device, or a CU, DU or other module, or a device under the open radio access network (O-RAN) architecture, such as an open CU, open DU and other devices.

[0187] 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.

[0188] In this application, a 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 circuitry in the aforementioned devices used to implement processing functions, which may implement or execute the various 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 methods disclosed in this application may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0189] 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.

[0190] Optionally, an embodiment of the present application further provides a chip system, comprising: at least one processor and an interface, wherein the at least one processor is coupled to a memory via the interface, and when the at least one processor executes a computer program or instruction in the memory, the chip system executes the 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 embodiments of the present application.

[0191] The memory in the present application can also be a circuit or any other device capable of realizing a storage function, for storing program instructions and / or data. A 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 can 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).

[0192] It should be understood that in the description of this application, unless otherwise specified, " / " indicates that the objects associated with each other are in an "or" relationship. For example, A / B can mean A or B; where A and B can be singular or plural. Also, in the description of this application, unless otherwise specified, "multiple" means 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 or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural. In addition, to facilitate the clear description of the technical solutions of the embodiments of this application, in the embodiments of this application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and words such as "first" and "second" do not necessarily mean different. At the same time, in the embodiments of this 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 this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner to facilitate understanding.

[0193] 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 the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can 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 can be transmitted from one website, computer, server or data center to another website, computer, server or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0194] 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 can understand and implement other changes to the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0195] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

[0196] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0197] The components in the device of the embodiment of the present application can be merged, divided, or 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.

[0198] In this application, under the premise of no logical contradiction, the examples can reference each other, for example, the methods and / or terms between method embodiments can reference each other, for example, the functions and / or terms between device embodiments can reference each other, for example, the functions and / or terms between device examples and method examples can 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 For each set of characteristic subspace waves The number of beams in the beam.

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, where K is a large 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 to 15, and the second communication device being used to implement the method according to any one of claims 16 to 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.

47. A computer program product, characterized in that The computer program product comprises program instructions, and when the program instructions are executed, the method according to any one of claims 1 to 20 is implemented.

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