Method and device for reporting channel state information

Abstract

The invention provides a method and a device for reporting channel state information (CSI), which can reduce the signaling overhead of CSI reporting. The method comprises the following steps: receiving a reference signal from network equipment; performing channel measurement according to the reference signal, and sending a first CSI to a network device; wherein the first CSI comprises first indication information, second indication information and third indication information, the first indication information is used for indicating a first projection coefficient, the second indication information is used for indicating a second projection coefficient, the third indication information is used for indicating each group of projection substrates in M groups of projection substrates, and the M groups of projection substrates correspond to M groups of first substrates; the projection substrates included in any two groups of projection substrates in the M groups of projection substrates are not completely the same, the first projection coefficient, the second projection coefficient and the M groups of projection substrates are used for determining M groups of first substrates, the first substrates are used for determining a precoding matrix indicator PMI, and M is an integer greater than 1.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communications, and in particular to a method and apparatus for reporting channel state information in the field of communications. Background Art

[0002] Communication systems widely utilize multiple-user multiple-input multiple-output (MIMO) technology. MIMO technology uses multiple transmit antennas and receive antennas in both network devices and terminal devices, respectively. This technology utilizes a multi-layer parallel transmission mode to provide higher data transmission rates and improve communication quality. When using MIMO technology, network devices must precode data before sending it to terminal devices. This precoding method relies on channel state information (CSI). CSI represents the channel properties of a communication link, and the accuracy of CSI acquired by network devices largely determines the performance of the MIMO system.

[0003] Generally, in time division duplexing (TDD) systems, uplink and downlink channels use the same frequency band and therefore exhibit reciprocity. Network devices can leverage this reciprocity to obtain the CSI of the downlink channel through the uplink channel and perform precoding. However, in frequency division duplexing (FDD) systems, because the separation between the uplink and downlink frequency bands is greater than the bandwidth, the uplink and downlink channels lack complete reciprocity, requiring the terminal device to provide feedback on the downlink CSI to the network device. The CSI fed back by the terminal device to the network device typically includes parameters such as the precoding matrix indicator (PMI), rank indicator (RI), and channel quality indicator (CQI). The PMI indicates the precoding matrix recommended by the terminal device for data transmission from a predefined codebook. The RI indicates the number of data layers recommended by the terminal device for simultaneous transmission to the terminal device on the same time-frequency resources. The CQI indicates the channel quality of the terminal device and is used to recommend the appropriate modulation scheme and coding rate to the network device.

[0004] The current CSI reporting method has a large signaling overhead. Summary of the Invention

[0005] The present application provides a method and apparatus for reporting channel state information, which can reduce the signaling overhead of CSI reporting.

[0006] In a first aspect, a method for reporting channel state information is provided, comprising: receiving a reference signal from a network device; performing channel measurement based on the reference signal, and sending a first CSI to the network device; wherein the first CSI includes first indication information, second indication information, and third indication information, the first indication information being used to indicate a first projection coefficient, the second indication information being used to indicate a second projection coefficient, the third indication information being used to indicate each group of projection bases in M ​​groups of projection bases, the M groups of projection bases corresponding to M groups of first bases, the projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same, the first projection coefficient, the second projection coefficient, and the M groups of projection bases are used to determine the M groups of first bases, the first base is used to determine a precoding matrix indication PMI, and M is an integer greater than 1.

[0007] It should be understood that a reference signal, also known as a pilot signal or downlink reference signal, is a known signal sent by a network device to a terminal device for channel measurement. The M groups of first bases are obtained by dividing multiple first bases, and the number of first bases in each group of the M groups of first bases is greater than or equal to one.

[0008] In the channel state information reporting method of the present application, when the terminal device needs to report multiple first bases, the terminal device only needs to report the first projection coefficients, the second projection coefficients and M groups of projection bases used to reconstruct the multiple first bases. Compared with reporting multiple known bases and larger dimensional combination coefficients used to fit each of the multiple first bases, the signaling overhead of CSI reporting is smaller.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the M groups of first bases are obtained by dividing the N first bases according to the sizes of their eigenvalues, and in the M groups of first bases, the eigenvalue of the first base with the smallest eigenvalue in the p-th group of first bases is greater than the eigenvalue of the first base with the largest eigenvalue in the q-th group of first bases, the number of projection bases in the p-th group of projection bases corresponding to the p-th group of first bases is less than the number of projection bases in the q-th group of projection bases corresponding to the q-th group of first bases, p and q are different, p and q are integers greater than or equal to 1 and less than or equal to M, and N is an integer greater than 1.

[0010] It should be understood that, through the above technical solution, compared to reconstructing N first bases using the same number of projection bases, since the first bases of the subset of M groups of first bases with larger eigenvalues ​​can be reconstructed using fewer projection bases, the dimensions of the second projection coefficients corresponding to the first bases of the subset of M groups of first bases with larger eigenvalues ​​are smaller, thereby reducing signaling overhead. In addition, since the first bases with larger eigenvalues ​​vary less over time than the first bases with smaller eigenvalues, dividing the N first bases according to their eigenvalues ​​and making the first bases with smaller eigenvalues ​​correspond to more projection bases and the first bases with larger eigenvalues ​​correspond to fewer projection bases can reduce signaling overhead while increasing the accuracy of the first bases reconstructed by the network device.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the first projection coefficient is determined based on the first basis and the second basis, the second basis is reported through the second CSI, and the second CSI is reported before the first CSI; and / or, the second projection coefficient is determined based on the M groups of projection bases, the first projection coefficient, the first basis and the second basis.

[0012] It should be understood that since the channel characteristics change slowly in actual channel propagation, there is a strong correlation between the first basis and the second basis determined by historically reporting the second CSI. Therefore, the terminal device can report the linear combination coefficient of the second basis (first projection coefficient) and the difference between the first basis and the second basis (second projection coefficient and M groups of projection basis). Since the network device knows the second basis, the network device can reconstruct the first basis based on the first projection coefficient, the second projection coefficient, the M groups of projection basis and the second basis. In this way, the signaling overhead of CSI reporting is relatively small.

[0013] In combination with the first aspect, in some implementations of the first aspect, the M is agreed upon by a protocol, or the network device is configured through signaling.

[0014] It should be understood that M is agreed upon in the protocol or configured by the network device through signaling, which can be understood as M itself being agreed upon in the protocol or configured by the network device through signaling. For example, M may be 2 or 3 as agreed upon in the protocol.

[0015] In conjunction with the first aspect, in certain implementations of the first aspect, the number of first substrates included in each of the M groups of first substrates is configured by the network device through signaling. In conjunction with the first aspect, in certain implementations of the first aspect, the number of first substrates included in each of the M-1 groups of first substrates in the N and M groups of first substrates is configured by the network device through signaling.

[0016] It should be understood that, in the case where N is configured through signaling, and the number of first substrates included in each of the M-1 groups of first substrates in the M groups of first substrates, the number of first substrates included in the remaining group of first substrates in the M groups of first substrates excluding the M-1 group of first substrates can be determined. In this way, compared with the case where the network device configures the number of first substrates included in each of the M groups of first substrates through signaling, the signaling overhead is smaller.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the ratio of the number of first substrates included in each of the N and M-1 groups of first substrates in the M groups of first substrates to N is configured by the network device through signaling.

[0018] It should be understood that the terminal device can use the ratio of the number of first substrates included in each group of first substrates in N and M-1 groups of first substrates to N to calculate the number of first substrates included in each group of first substrates in the M-1 group of first substrates, and calculate the number of first substrates included in the remaining group of first substrates in the M groups of first substrates except the M-1 group of first substrates based on the number of first substrates included in each group of first substrates in the M-1 group of first substrates and N. In this way, compared with the network device configuring the number of first substrates included in each group of first substrates in the M groups of first substrates through signaling, the signaling overhead is smaller.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the M-1 group of first substrates is the front M-1 group of first substrates or the rear M-1 group of first substrates among the M groups of first substrates.

[0020] It should be understood that the first M-1 groups of first bases or the last M-1 groups of first bases can be understood as the first M-1 groups of first bases or the last M-1 groups of first bases in the M groups of first base sequence obtained after the terminal device sorts the M groups of first bases according to a certain sorting rule.

[0021] In combination with the first aspect, in certain implementations of the first aspect, the group identifier of the M-1 group of first bases is agreed upon by protocol.

[0022] It should be understood that the group identifier can be understood as information used to indicate each group of first substrates, and can also be called a group index, a group serial number, etc.

[0023] In conjunction with the first aspect, in certain implementations of the first aspect, the number of projection substrates included in each of the M groups of projection substrates is configured by the network device through signaling. In conjunction with the first aspect, in certain implementations of the first aspect, the ratio of the number K of projection substrates included in the sth group of projection substrates in the M groups of projection substrates to the number of projection substrates included in each of the remaining groups of projection substrates in the M groups of projection substrates, excluding the sth group of projection substrates, to K is configured by the network device through signaling, where s is an integer greater than or equal to 1 and less than or equal to M, and K is an integer greater than 0.

[0024] In combination with the first aspect, in some implementations of the first aspect, the sth group of projection substrates is the first group of projection substrates or the last group of projection substrates among the M groups of projection substrates.

[0025] It should be understood that the first group of projection bases or the last group of projection bases may be the first group of projection bases or the last group of projection bases in a sequence of M groups of projection bases obtained after the terminal device sorts the M groups of projection bases. For example, the terminal device may sort the projection bases according to the number of projection bases included in each group, for example, sorting them in ascending order of the number of projection bases. In this case, the first group of projection bases is the group including the largest number of projection bases, and the last group of projection bases is the group including the smallest number of projection bases.

[0026] In combination with the first aspect, in some implementations of the first aspect, the projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from a projection base set, and e is an integer greater than 1 and less than or equal to M.

[0027] It should be understood that a group of projection bases corresponding to each group of first bases in the M groups of first bases is determined from the entire set of projection bases, and any two groups of projection bases in the M groups of projection bases may or may not include the same projection base.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the projection substrates included in the e-th group of projection substrates in the M groups of projection substrates are selected from the projection substrates included in the f-th group of projection substrates, and the f-th group of projection substrates is the group of projection substrates including the largest number of projection substrates in the M groups of projection substrates, and f is an integer greater than 1 and less than or equal to M.

[0029] It should be understood that through the above technical solution, compared with selecting the projection bases included in each group of projection bases in all other groups of projection bases from the entire set of projection bases, the selection range of the projection bases included in each group of projection bases in all other groups of projection bases is smaller, and the possible combinations of the projection bases included in each group of projection bases in all other groups of projection bases are fewer, so that the signaling overhead of reporting all other groups of projection bases is smaller.

[0030] In combination with the first aspect, in some implementations of the first aspect, the third indication information is reported in the form of a bit map or a combination number.

[0031] It should be understood that when the third indication information is reported via a bitmap, the number of bits in the third indication information corresponds to the number of selectable projection substrates, and each bit in the third indication information corresponds one-to-one to a selectable projection substrate, with each bit used to indicate whether its corresponding projection substrate is selected. When the third indication information is reported via a combination number, the number of bits in the third indication information can be determined using the following formula: log2P, where P is the number of possible combinations of projection substrates included in each group of projection substrates. If the value obtained from this formula is not an integer, the number of bits in the third indication information is determined as the integer greater than and closest to the value. Different combinations of the number of bits in the third indication information indicate different combinations of projection substrates. In this way, the network device can determine the projection substrates included in each group of projection substrates based on the third indication information corresponding to each group of projection substrates.

[0032] In combination with the first aspect, in certain implementations of the first aspect, the first amplitude-normalized value of the first projection coefficient corresponding to the i-th first basis among the N first basis is the maximum amplitude value of the first projection coefficient corresponding to the i-th first basis, and the second amplitude-normalized value of the second projection coefficient corresponding to the i-th first basis is the maximum amplitude value of the second projection coefficient corresponding to the i-th first basis, where i is an integer greater than or equal to 1 and less than or equal to N; the first CSI also includes fourth indication information, and the fourth indication information is used to indicate the ratio of the first amplitude-normalized value to the second amplitude-normalized value.

[0033] It should be understood that the first projection coefficients include coefficients corresponding to each of the N first bases. For example, the i-th column of the first projection coefficients may be the first projection coefficients corresponding to the i-th first base in the N first bases. The terminal device typically normalizes the first and second projection coefficients before quantizing the amplitude and phase, respectively, and reporting them.

[0034] In combination with the first aspect, in some implementations of the first aspect, the first basis is a spatial basis, a frequency domain basis, or a space-frequency domain basis, or the first basis includes a spatial basis and a frequency domain basis.

[0035] In a second aspect, another method for reporting channel state information is provided, including: receiving a reference signal from a network device; performing channel measurement based on the reference signal, and sending a first CSI to the network device; wherein the first CSI includes first indication information, second indication information, third indication information, and fourth indication information, the first indication information is used to indicate a first projection coefficient, the second indication information is used to indicate a second projection coefficient, the third indication information is used to indicate each group of projection bases in M ​​groups of projection bases, the M groups of projection bases correspond to M groups of first bases, the projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same, the first projection coefficient, the second projection coefficient, and the M groups of projection bases are used to determine the M groups of first bases. Basis, the M groups of first bases are obtained by dividing N first bases, and the fourth indication information is used to indicate the ratio of the first amplitude normalized value of the first projection coefficient corresponding to the i-th first basis in the N first bases to the second amplitude normalized value of the second projection coefficient corresponding to the i-th first basis in the N first bases, the first amplitude normalized value is the maximum amplitude of the first projection coefficient corresponding to the i-th first basis, the second amplitude normalized value is the maximum amplitude of the second projection coefficient corresponding to the i-th first basis, i is an integer greater than or equal to 1 and less than or equal to N, N is a positive integer greater than 1, M is an integer greater than 1 and less than N, and the first basis is used to determine the precoding matrix indication PMI or the channel covariance matrix.

[0036] In a third aspect, a channel state information reporting device is provided, configured to execute the method in any possible implementation of the first aspect. Specifically, the device includes a module configured to execute the method in any possible implementation of the first aspect.

[0037] In a fourth aspect, another channel state information reporting device is provided, configured to execute the method in any possible implementation of the second aspect. Specifically, the device includes a module configured to execute the method in any possible implementation of the second aspect.

[0038] In a fifth aspect, the present application provides another channel state information reporting device, comprising a processor coupled to a memory and configured to execute instructions in the memory to implement the method of any possible implementation of the first or second aspect described above. Optionally, the device further comprises a memory. Optionally, the device further comprises a communication interface, the processor coupled to the communication interface.

[0039] In one implementation, the apparatus is a terminal device. When the apparatus is a terminal device, the communication interface may be a transceiver, or an input / output interface.

[0040] In another implementation, the device is a chip configured in a terminal device. When the device is a chip configured in a terminal device, the communication interface may be an input / output interface.

[0041] In a sixth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method of any possible implementation of the first or second aspect.

[0042] In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation of the processor and various circuits.

[0043] In a seventh aspect, a processing device is provided, comprising a processor and a memory. The processor is configured to read instructions stored in the memory and receive signals via a receiver and transmit signals via a transmitter to execute the method of any possible implementation of the first or second aspect.

[0044] Optionally, there are one or more processors and one or more memories.

[0045] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0046] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or set on different chips. This application does not limit the type of memory and the setting method of the memory and the processor.

[0047] It should be understood that related data interaction processes, such as sending indication information, can be processes for outputting indication information from a processor, and receiving capability information can be processes for receiving input capability information from a processor. Specifically, the output data of the processor can be output to a transmitter, and the input data received by the processor can come from a receiver. The transmitter and receiver can be collectively referred to as a transceiver.

[0048] The processing device in the seventh aspect mentioned above can be a chip. The processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. The memory can be integrated in the processor or can be located outside the processor and exist independently.

[0049] In an eighth aspect, a computer program product is provided, comprising: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute a method in any possible implementation of the first or second aspect.

[0050] In the ninth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions) which, when run on a computer, enables the computer to execute the method in any possible implementation of the first or second aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of a communication system used in an embodiment of the present application;

[0052] Figure 2 A flowchart of a CSI reporting method is shown;

[0053] Figure 3 A flowchart of a CSI reporting method provided in an embodiment of the present application;

[0054] Figure 4 A schematic diagram of a method for determining M groups of projection bases provided in an embodiment of the present application;

[0055] Figure 5 A schematic diagram of another method for determining M groups of projection bases provided in an embodiment of the present application;

[0056] Figure 6 A schematic diagram of another method for determining M groups of projection bases provided in an embodiment of the present application;

[0057] Figure 7Schematic diagram of another method for determining the M - group projection basis provided by the embodiments of this application;

[0058] Figure 8 Schematic block diagram of a CSI reporting device provided by the embodiments of this application;

[0059] Figure 9 Schematic block diagram of another CSI reporting device provided by the embodiments of this application. Detailed implementation manners

[0060] Next, the technical solutions in this application will be described in conjunction with the accompanying drawings.

[0061] In the embodiments of this application, terms such as "first" and "second" are used to distinguish identical or similar items with basically the same functions and roles. For example, the first value and the second value are only used to distinguish different values, and do not limit their sequence. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different.

[0062] It should be noted that in the embodiments of this application, words such as "exemplarily" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplarily" or "for example" in this application should not be construed as more preferred or more advantageous than other embodiments or design solutions. Exactly speaking, using words such as "exemplarily" or "for example" aims to present related concepts in a specific way.

[0063] In the embodiments of this application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents that the associated objects before and after are an "or" relationship. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, c can be single or multiple.

[0064] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR), future evolved communication systems, such as sixth generation (6G) system, etc.

[0065] The terminal device in the embodiments of the present application may also be referred to as: user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent or user device, etc.

[0066] The terminal device may be a device that provides voice / data connectivity to users, such as a handheld device or vehicle-mounted device with wireless connection function. At present, some examples of terminal devices include: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (PLMNs). The present application does not limit the terminal equipment in the network (PLMN), etc.

[0067] By way of example and not limitation, in this application, a terminal device may be a terminal device in an Internet of Things (IoT) system. The IoT is an important component of the future development of information technology. Its main technical feature is connecting objects to the Internet through communication technologies, thereby realizing an intelligent network that interconnects humans and machines, and things and things. For example, the terminal device in the embodiments of this application may be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for wearable devices that apply wearable technology to intelligently design and develop wearable devices, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that can be worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices; they can also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve full or partial functions independently of smartphones, such as smart watches or smart glasses, as well as those that focus on a specific application function and require cooperation with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0068] As an example and not a limitation, in an embodiment of the present application, the terminal device may also be a terminal device in a machine type communication (MTC). In addition, the terminal device may also be an on-board module, on-board module, on-board component, on-board chip or on-board unit built into the vehicle as one or more components or units, and the vehicle may implement the method provided in the present application through the built-in on-board module, on-board module, on-board component, on-board chip or on-board unit. Therefore, the embodiment of the present application may also be applied to the Internet of Vehicles, such as vehicle to everything (V2X), long term evolution-vehicle (LTE-V), vehicle-to-vehicle (V2V) technology, etc.

[0069] The network device involved in this application can be a device that communicates with a terminal device. The network device can also be called an access network device or a wireless access network device. It can be a transmission reception point (TRP), an evolved NodeB (eNB or eNodeB) in an LTE system, a home base station (for example, home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless controller in a cloud radio access network (CRAN) scenario, or the network device can be a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in a 5G network, or a network device in a future evolved PLMN network, etc. It can also be an access point (AP) in a WLAN, or a gNB in ​​an NR system. The above-mentioned network devices can also be urban base stations, micro base stations, pico base stations, femto base stations, etc., and this application does not limit this.

[0070] The following introduces some technical terms involved in this application.

[0071] 1. Antenna port: This can be understood as a transmitting antenna recognized by a receiving device, or a receiving antenna that can be recognized by a transmitting device; or, a transmitting antenna or receiving antenna that can be distinguished in space, which can be referred to as a physical antenna.

[0072] 2. Frequency domain unit: A unit of frequency domain resources that can represent different frequency domain resource granularities. Frequency domain units may include, but are not limited to, a subband, a resource block (RB), a subcarrier, a resource block group (RBG), or a precoding resource block group (PRG). In addition, the frequency domain length of a frequency domain unit can be Y times the length of the CQI subband, where Y <= 1 and the value of Y can be 1 or 1 / 2.

[0073] 3. Spatial basis: It can also be called spatial basis vector, beam vector, spatial vector, spatial beam basis vector. One or more spatial bases constitute a spatial basis matrix. Each spatial basis corresponds to a transmitting beam of the transmitting device, and each element in the spatial basis can be represented as the weight of each antenna port. Based on the weights of each antenna port represented by each element in the spatial basis vector, the signals of each antenna port are linearly superimposed to form an area with a strong signal in a certain direction in space. Optionally, the spatial basis is taken from a two-dimensional discrete Fourier transform (DFT) matrix. Each column vector in the two-dimensional DFT matrix can be called a two-dimensional DFT vector. In other words, the spatial basis vector can be a two-dimensional DFT vector, and the two-dimensional DFT vector can generally be used to describe a beam formed by the superposition of a horizontal beam and a vertical beam. The linear combination of multiple spatial bases can obtain a new spatial basis.

[0074] 4. Frequency domain basis: It can also be called frequency domain vector or frequency domain basis vector, which is a vector that can be used to represent the change law of the channel in the frequency domain. One or more frequency domain bases constitute the frequency domain basis matrix. Each frequency domain basis can represent a change law. Since the signal can reach the receiving antenna through multiple paths from the transmitting antenna when it is transmitted through the wireless channel. Multipath delay causes frequency selective fading, which is the change of the frequency domain channel. Therefore, different frequency domain basis vectors can be used to represent the change law of the channel in the frequency domain caused by the delay on different transmission paths. Optionally, the frequency domain basis vector can select the DFT matrix or the inverse discrete Fourier transform (IDFT) matrix. (That is, the conjugate transpose matrix of the DFT matrix). In other words, the frequency domain basis can be a DFT vector or an IDFT vector. The linear combination of multiple frequency bases can obtain a new frequency domain basis.

[0075] The length of the frequency domain basis vector may be determined by the number of frequency domain units to be reported preconfigured in the reporting bandwidth, or by the length of the reporting bandwidth, or by a protocol predefined value. This application does not limit the length of the frequency domain basis vector. The reporting bandwidth may refer to the CSI reporting bandwidth (CSI-ReportingBand) carried in the CSI reporting configuration in the higher layer signaling (e.g., RRC message).

[0076] 5. Space-frequency domain basis: A vector used to represent the variation pattern of the channel in the joint space-frequency domain. One or more space-frequency domain bases constitute the space-frequency domain basis matrix. In this application, if the transmitting antenna of the network device is a single-polarized antenna, then the number of rows in the space-frequency joint vector matrix is ​​(M1×M2)×N f and the number of columns is N, or the number of rows is N and the number of columns is (M1×M2)×Nf , where M1 is the number of transmitting antenna ports in the horizontal direction of the network device, M2 is the number of transmitting antenna ports in the vertical direction of the network device, and N f is the number of frequency domain units, and N is the number of space-frequency joint vectors used to characterize the channel variation pattern in the joint space-frequency domain, that is, the number of multipaths, that is, the number of identifiable multipaths between the network device and the terminal device. It should be understood that if the transmitting antenna of the network device is a dual-polarized antenna, then the number of rows in the space-frequency joint vector matrix is ​​2×(M1×M2)×N f and the number of columns is N, or the number of rows is N and the number of columns is 2×(M1×M2)×N f Alternatively, the space-frequency domain basis may be determined by a two-dimensional DFT vector and a DFT vector. A linear combination of multiple space-frequency domain bases may yield a new space-frequency domain basis.

[0077] To facilitate understanding of the embodiments of this application, first Figure 1 A communication system applicable to the embodiments of the present application is described in detail.

[0078] Figure 1 Schematic diagram of a communication system 100 used in an embodiment of the present application. The communication system 100 may include at least one network device, such as Figure 1 The network device 110 shown; the communication system 100 may also include at least one terminal device, such as Figure 1 The terminal device 120 is shown. The network device 110 and the terminal device 120 can communicate via a wireless link. In one possible scenario, the network device 110 can act as a transmitter and the terminal device 120 can act as a receiver, with the network device 110 sending a signal to the terminal device 120. In another possible scenario, the network device 110 can act as a receiver and the terminal device 120 can act as a transmitter, with the terminal device 120 sending a signal to the network device 110.

[0079] Figure 1 The exemplary embodiment shows a network device 110 and a terminal device 120. Optionally, the communication system 100 may also include multiple network devices and / or multiple terminal devices. The network device 110 may be a router, a base station, etc., and the terminal device 120 may be a mobile phone, a tablet computer, a smart bracelet, etc., which is not limited in this embodiment of the present application.

[0080] The above-mentioned communication devices, such as Figure 1The network device 110 or terminal device 120 in the embodiment may be configured with multiple antennas. The multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also includes a transmitter chain and a receiver chain. Those skilled in the art will appreciate that each of them may include multiple components related to signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, or antennas, etc.). Therefore, the network device 110 and the terminal device 120 can communicate using multi-antenna technology.

[0081] Optionally, the communication system 100 may further include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0082] It should be understood that the method provided in the embodiment of the present application can be applied to various communication systems including the 5G new radio (NR) system. Figure 1 The communication system 100 shown is only an example. This application does not limit the specific architecture of the applicable system, nor does it limit the number and form of various devices included in each communication system.

[0083] In communication systems, MIMO technology is often used to improve spectral efficiency, thereby increasing data transmission rates and improving communication quality between network devices and end devices. When using MIMO technology, network devices must precode data before sending it to end devices. The network devices rely on CSI (Channel Information Score) to determine how to perform this precoding. The accuracy of the CSI obtained by network devices largely determines the performance of the MIMO system.

[0084] Generally speaking, in TDD systems, uplink and downlink channels use the same frequency band, thus exhibiting reciprocity. Network equipment can leverage this reciprocity to obtain the downlink CSI from the uplink channel for precoding. In FDD systems, however, because the separation between the uplink and downlink frequency bands is greater than the bandwidth, reciprocity is not fully achieved between the uplink and downlink channels. Terminal devices must provide feedback on the downlink CSI to the network equipment.

[0085] In one possible implementation, the network device can Figure 2 The method 200 shown in FIG. Figure 2 As shown, the method 200 includes the following steps:

[0086] S201: A network device sends channel measurement configuration information to a terminal device. Correspondingly, the terminal device receives the channel measurement configuration information from the network device.

[0087] It should be understood that the measurement configuration information may include information for instructing the terminal device to perform channel measurement, time domain information for channel measurement, etc.

[0088] S202: The network device sends a pilot signal to the terminal device. Correspondingly, the terminal device receives the pilot signal from the network device. The pilot signal can be understood as a CSI-reference signal (RS).

[0089] S203: The terminal device determines CSI based on the pilot measurement result and sends the CSI to the network device. Correspondingly, the network device receives the CSI from the terminal device.

[0090] Optionally, the network device may send data to the terminal device based on the CSI from the terminal device.

[0091] The CSI fed back by the terminal device to the network device generally includes parameters such as PMI, RI, and CQI. PMI is used to indicate the precoding matrix recommended by the terminal device for the network device to use for data transmission from a predefined codebook. RI indicates the number of data layers recommended by the terminal device for the network device to transmit simultaneously to the terminal device on the same time-frequency resources. CQI indicates the channel quality of the terminal device and is used to recommend the appropriate modulation method and coding rate to the network device.

[0092] In order to improve the accuracy of the PMI reported by the terminal device, a codebook based on the spatial domain basis, frequency domain basis or space-frequency domain basis of the downlink channel statistical information is currently proposed. The spatial domain basis based on the statistical downlink channel statistical information can be obtained by the eigenvectors of the spatial covariance matrix of the downlink channel, the frequency domain basis based on the statistical downlink channel statistical information can be obtained by the eigenvectors of the frequency domain covariance matrix of the downlink channel, and the space-frequency domain basis based on the statistical downlink channel statistical information can be obtained by the eigenvectors of the space-frequency domain joint covariance matrix of the downlink channel. The codebook usually uses a linear combination of a set of known bases of terminal devices and network devices to approximate the spatial domain basis, frequency domain basis or space-frequency domain basis based on the downlink channel statistical information.

[0093] It should be understood that for a channel H with dimension a×k, where a is the number of transmit antenna ports of the network device and k is the number of frequency domain units, the spatial covariance matrix of the channel can be expressed as H×H H The expectation of the channel frequency domain covariance matrix can be expressed as H H ×H expectation, further, H can be vectorized into a vector h of dimension (a×k)×1, then the spatial-frequency domain joint covariance matrix of the channel can be expressed as h×h H expectations.

[0094] It should be understood that approximation can be understood as fitting or approximation, etc. For example, approximating base 2 through base 1 can be understood as obtaining base 3 through base 1 and linear combination coefficients, and base 3 is infinitely close to base 2, which is an approximation of base 2.

[0095] The following describes how to determine the channel matrix or precoding matrix with reference to two examples.

[0096] In one example, the channel matrix or precoding matrix is ​​determined by approximating the basis corresponding to each of the frequency domain basis and the spatial domain basis. Then, the channel corresponding to a receiving antenna port of the terminal device or the precoding matrix corresponding to a data stream can be obtained by the following formula: H = S × C1 × C2 × F H ×C3, where H is the channel matrix or precoding matrix of a×k dimensions, a is the number of transmit antenna ports of the network device, and k is the number of frequency domain units; S is the spatial basis matrix of a×b dimensions, and b is the number of spatial basis in S; C1 is the combination coefficient of the spatial projection basis matrix of b×c dimensions, and c is the number of reconstructed spatial basis; SC1 is the reconstructed spatial basis matrix; F is the frequency domain basis matrix of k×j dimensions; j is the number of frequency domain basis in F; C3 is the combination coefficient of the frequency domain projection basis matrix of d×j dimensions, and d is the number of reconstructed frequency domain basis; F H C3 is the reconstructed frequency domain basis matrix, F H is the conjugate transpose of the frequency domain basis matrix, and C2 is the combined coefficient of the reconstructed spatial basis matrix and the reconstructed frequency domain basis matrix of c×d dimensions. The terminal device needs to report S, C1, F, and C3 at a longer period and C2 at a shorter period. For example, S, C1, F, and C3 may be reported every 60 minutes, and C2 may be reported every 10 minutes.

[0097] In another example, the channel matrix or precoding matrix is ​​determined by approximating the basis corresponding to the space-frequency domain basis. The channel matrix or precoding matrix can be obtained by the following formula: H = B × C4 × C5, where H is the channel corresponding to a receiving antenna port of a terminal device of (a × k) × 1 dimensions or the precoding matrix corresponding to a data stream, a is the number of transmitting antenna ports of the network device, and k is the number of frequency domain units; B is the space-frequency domain basis matrix of (a × k) × u ​​dimensions, u is the number of space-frequency domain basis in B; C4 is the combination coefficient of the space-frequency domain basis matrix of u × v dimensions, v is the number of reconstructed space-frequency domain basis; B * C4 is the reconstructed space-frequency domain basis, and C5 is the combination coefficient of the reconstructed space-frequency domain basis matrix of v × 1 dimensions. Among them, the terminal device needs to report B and C4 with a longer period and report C5 with a shorter period. For example, B and C4 are reported every 60 minutes, and C5 is reported every 10 minutes.

[0098] However, with such a CSI reporting method, for each of the multiple bases that the terminal device needs to report, the terminal device needs to fit each base through multiple known bases, so that the CSI reported by the terminal device each time includes not only multiple known bases for fitting each of the multiple bases, but also combination coefficients of larger dimensions, which makes the current signaling overhead large.

[0099] In order to solve the above technical problems, the present application provides a CSI reporting method and reporting device. When a terminal device needs to report multiple first bases, the terminal device only needs to report the first projection coefficients, second projection coefficients and M groups of projection bases used to reconstruct the multiple first bases. Compared with reporting multiple known bases and larger dimensional combination coefficients used to fit each of the multiple first bases, the signaling overhead of CSI reporting is smaller.

[0100] The following combination Figures 3 to 7 The CSI reporting method of this application is described in detail. The embodiments shown in this application illustrate the CSI reporting method provided by this application from the perspective of device interaction. The specific form and number of each device shown are merely examples and should not constitute any limitation on the implementation of the method provided by this application. Below, the CSI reporting method of the embodiment of this application is described in detail, taking a terminal device and a network device as the execution entities.

[0101] It should be understood that the terminal device can be the terminal device itself, or it can be a chip, chip system or processor that supports the terminal device to implement the CSI reporting method, or it can be a logical module or software that can implement all or part of the terminal device; the network device can be the network device itself, or it can be a chip, chip system or processor that supports the network device to implement the CSI reporting method, or it can be a logical module or software that can implement all or part of the network device. This application does not make specific limitations on this.

[0102] Figure 3 The present invention provides a flow chart of a CSI reporting method 300. The method 300 includes the following steps:

[0103] S301: A network device sends a reference signal (RS) to a terminal device. Correspondingly, the terminal device receives the reference signal from the network device.

[0104] It should be understood that the reference signal can also be called a pilot signal or a downlink reference signal, which is a known signal sent by a network device to a terminal device for channel measurement. The reference signal can be, but is not limited to, any one or more of the following: CSI-RS, cell specific reference signal (CS-RS), UE specific reference signal (US-RS), demodulation reference signal (DMRS), and synchronization system / physical broadcast channel block (SS / PBCH block). Among them, SS / PBCH block can be referred to as SSB.

[0105] S302. The terminal device performs channel measurement based on the reference signal and sends the first CSI to the network device. Correspondingly, the network device receives the first CSI from the terminal device. The first CSI includes first indication information, second indication information, and third indication information. The first indication information is used to indicate the first projection coefficient, the second indication information is used to indicate the second projection coefficient, and the third indication information is used to indicate each group of projection bases in the M groups of projection bases. The M groups of projection bases correspond to the M groups of first bases. The projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same. The first projection coefficient, the second projection coefficient, and the M groups of projection bases are used to determine the M groups of first bases. The first base is used to determine the precoding matrix indication PMI, and M is an integer greater than 1.

[0106] It should be understood that after the terminal device performs channel measurement based on the reference signal, it can determine multiple first bases. The first projection coefficient, the second projection coefficient and the M groups of projection bases are used to determine the M groups of first bases, which can be understood as the network device being able to approximate the multiple first bases through the first projection coefficient, the second projection coefficient and the M groups of projection bases, or the network device being able to reconstruct the multiple first bases through the first projection coefficient, the second projection coefficient and the M groups of projection bases. The M groups of first bases are obtained by dividing the multiple first bases, and the number of each group of first bases in the M groups of first bases is greater than or equal to 1. Exemplarily, the multiple first bases include a first base 1, a first base 2, a first base 3 and a first base 4, and the terminal device divides the four first bases into two groups of first bases, wherein one group of first bases includes the first base 1, the first base 2 and the first base 3, and the other group of first bases includes the first base 4.

[0107] Optionally, the number of the first projection coefficients is M, and the number of the second projection coefficients is M, that is, each of the M groups of first bases corresponds to one first projection coefficient and one second projection coefficient.

[0108] The M groups of projection substrates corresponding to the M groups of first substrates can be understood as a one-to-one correspondence between the M groups of projection substrates and the M groups of first substrates. For example, assuming M is 2, the two groups of projection substrates include a first group of projection substrates and a second group of projection substrates; and the two groups of first substrates include a first group of first substrates and a second group of first substrates. In this case, the first group of projection substrates can correspond to the first group of first substrates, and the second group of first substrates can correspond to the second group of first substrates.

[0109] Optionally, the M groups of projection bases are determined based on the M groups of first bases, that is, after the terminal device divides multiple first bases into M groups of first bases, it determines a group of projection bases based on each group of first bases in the first bases to obtain M groups of projection bases.

[0110] In the channel state information reporting method of the present application, when the terminal device needs to report multiple first bases, the terminal device only needs to report the first projection coefficients, the second projection coefficients and M groups of projection bases used to reconstruct the multiple first bases. Compared with reporting multiple known bases and larger dimensional combination coefficients used to fit each of the multiple first bases, the signaling overhead of CSI reporting is smaller.

[0111] The following describes in detail how to determine the first projection coefficient and the second projection coefficient.

[0112] As an optional embodiment, the first projection coefficient is determined based on the first basis and the second basis, the second basis is reported through the second CSI, and the second CSI is reported before the first CSI; and / or, the second projection coefficient is determined based on M groups of projection basis, the first projection coefficient, the first basis and the second basis.

[0113] It should be understood that since the channel characteristics change slowly in actual channel propagation, there is a strong correlation between the first basis and the second basis determined by historically reporting the second CSI. Therefore, the terminal device can report the linear combination coefficient of the second basis (first projection coefficient) and the difference between the first basis and the second basis (second projection coefficient and M groups of projection basis). Since the network device knows the second basis, the network device can reconstruct the first basis based on the first projection coefficient, the second projection coefficient, the M groups of projection basis and the second basis. In this way, the signaling overhead of CSI reporting is relatively small.

[0114] It is understood that the first projection coefficients corresponding to the M groups of first substrates may be determined by the terminal device based on each group of first substrates, and / or the second projection coefficients corresponding to the M groups of first substrates may be determined by the terminal device based on each group of first substrates. The following describes in detail the method for determining the first and second projection coefficients, taking the first group of first substrates among the M groups of first substrates as an example.

[0115] In one possible implementation, the first projection coefficient corresponding to the first group of first bases can be calculated using the following formula: Among them, C6 is the first projection coefficient corresponding to the first group of the first basis, U t is the first group of first basis corresponding to time t, is the conjugate transpose of the matrix consisting of N second bases corresponding to time t-1, where time t-1 refers to the time between time t, and N is the number of first bases.

[0116] It should be understood that the first projection coefficient corresponding to the first group of first bases can be an N×h-dimensional matrix, where h is the number of first bases included in the first group of first bases, and the coefficient of the i-th column in the N×h-dimensional matrix corresponds to the i-th first base in the first group of first bases, and i is an integer greater than or equal to 1 and less than or equal to h. Time t can be understood as the time when the terminal device reports the first CSI, and time t-1 can be understood as the time when the terminal device reports the second CSI. Optionally, the second CSI can be the CSI last reported by the terminal device before the first CSI. For example, assuming that the terminal device reports CSI every 5 minutes, and the time (t time) of reporting the first CSI is 10:05, the time (t-1 time) of reporting the second CSI can be 10:00.

[0117] In a possible implementation, the second projection coefficient corresponding to the first group of first bases is calculated using the following formula: C7=D + ×ΔU t , where C7 is the second projection coefficient corresponding to the first base of the first group, U t is the first group of first basis corresponding to time t, C6 is the first projection coefficient corresponding to the first group of first basis, is the matrix composed of N second bases corresponding to time t-1, ΔU t For U t and The quantized difference space, D + is the pseudo-inverse of D, where D is a matrix consisting of a set of projected bases corresponding to the first set of first bases.

[0118] It should be understood that the second projection coefficients corresponding to the first group of first bases can be an m×h dimensional matrix, where m is the number of a group of projection bases corresponding to the first group of first bases, and h is the number of first bases included in the first group of first bases. The i-th column coefficient in the m×h dimensional matrix corresponds to the i-th first base in the first group of first bases, and i is an integer greater than or equal to 1 and less than or equal to h.

[0119] It should be understood that since the M groups of projection substrates correspond to the M groups of first substrates in a one-to-one correspondence and the M groups of projection substrates are not completely the same, the D corresponding to each group of first substrates in the M groups of first substrates is different.

[0120] In the above formula for determining the first projection coefficient and the second projection coefficient, It can be reconstructed by the terminal device according to the second CSI.

[0121] It should be understood that after the terminal device determines the second CSI, the second basis can be reconstructed according to the indication information for reconstructing the second basis included in the second CSI. The number of the second basis can be the same as the number of the first basis.

[0122] In one possible implementation, the first group of first bases can be reconstructed using the following formula: in, is the reconstructed first group of first basis, C6 is the first projection coefficient corresponding to the first group of first basis, C7 is the second projection coefficient corresponding to the first group of first basis, and D is a matrix composed of a group of projection basis corresponding to the first group of first basis.

[0123] It can be seen from this that the network device can reconstruct M groups of first bases based on the first projection coefficients corresponding to each group of first bases in the M groups of first bases, the second projection coefficients corresponding to each group of first bases in the M groups of first bases, and the M groups of projection bases, so that the terminal device does not need to report the complete M groups of first bases, and the signaling overhead is relatively small.

[0124] It should be understood that for the first substrates of the M groups of first substrates except the first group of first substrates, the first projection coefficients and the second projection coefficients corresponding to each group of first substrates can also be determined in the same manner. Please refer to the description above and will not be repeated here.

[0125] As an optional embodiment, M groups of first bases are obtained by dividing N first bases according to the sizes of their eigenvalues. In the M groups of first bases, the eigenvalue of the first base with the smallest eigenvalue in the p-th group of first bases is greater than the eigenvalue of the first base with the largest eigenvalue in the q-th group of first bases. The number of projection bases in the p-th group of projection bases corresponding to the p-th group of first bases is less than the number of projection bases in the q-th group of projection bases corresponding to the q-th group of first bases. p and q are different, and p and q are integers greater than or equal to 1 and less than or equal to M. N is an integer greater than 1.

[0126] Through the above technical solution, compared to reconstructing N first bases using the same number of projection bases, since the first bases of some groups with larger eigenvalues ​​in the M groups of first bases can be reconstructed using fewer projection bases, the dimensions of the second projection coefficients corresponding to the first bases of some groups with larger eigenvalues ​​in the M groups of first bases are smaller, thereby reducing signaling overhead. In addition, since the first bases with larger eigenvalues ​​vary less over time than the first bases with smaller eigenvalues, dividing the N first bases according to their eigenvalues ​​and assigning more projection bases to first bases with smaller eigenvalues ​​and fewer projection bases to first bases with larger eigenvalues ​​can reduce signaling overhead while increasing the accuracy of the first bases reconstructed by the network device.

[0127] The following describes in detail three ways for the terminal device to determine M groups of projection bases.

[0128] In a first approach, the projection bases included in each of the M groups of projection bases are selected from the projection base set. For example, the projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from the projection base set, where e is an integer greater than 1 and less than or equal to M.

[0129] It should be understood that the projection substrates included in any two groups of projection substrates in the M groups may or may not be the same projection substrates. Figure 4 As shown, the full set of projection bases includes projection bases 1 to 9. The terminal device selects a first group of projection bases from projection bases 1 to 9: projection bases 1 to 5; and selects a second group of projection bases from projection bases 1 to 9: projection bases 6, 7, and 8. In this case, the first group of projection bases and the second group of projection bases do not have the same projection base. In another example, as Figure 5As shown, the full set of projection bases includes projection bases 1 to projection bases 9. The terminal device selects a first group of projection bases from projection bases 1 to projection bases 9: projection bases 1 to projection bases 5; and selects a second group of projection bases from projection bases 1 to projection bases 9: projection bases 4, projection bases 5, and projection bases 6. At this time, the first group of projection bases and the second group of projection bases have the same projection bases, that is, the first group of projection bases and the second group of projection bases both include projection bases 4 and projection bases 5.

[0130] In a second approach, except for the f-th group of projection bases in the M groups of projection bases, each group of projection bases in the remaining groups is selected from the projection bases included in the f-th group of projection bases. The f-th group of projection bases is the group of projection bases that includes the largest number of projection bases in the M groups of projection bases, and f is an integer greater than 1 and less than or equal to M. Taking the e-th group of projection bases in the M groups of projection bases as an example, the projection bases included in the e-th group of projection bases are selected from the projection bases included in the f-th group of projection bases.

[0131] In one exemplary embodiment, Figure 6 As shown, the full set of projection bases includes projection bases 1 to 9. The terminal device selects a first group of projection bases: projection bases 1 to 5 from projection bases 1 to 9; then selects the remaining groups of projection bases from the projection bases included in the first group of projection bases. For example, a second group of projection bases: projection base 2, projection base 3, and projection base 4 are selected from the projection bases included in the first group of projection bases. In the case where three projection bases in the second group of projection bases are selected from projection bases 1 to 9, the possible combinations of the three projection bases in the second group of projection bases are C 3 9, that is, 504 possible combinations; in the case where 3 projection bases in the second group of projection bases are selected from projection base 1 to projection base 5, the possible combinations of the 3 projection bases in the second group of projection bases are C 3 5, that is 60 possible combinations.

[0132] It can be seen that through the above-mentioned technical solution, compared with selecting the projection bases included in each group of projection bases in all other groups of projection bases from the entire set of projection bases, the selection range of the projection bases included in each group of projection bases in all other groups of projection bases is small, and the possible combinations of the projection bases included in each group of projection bases in all other groups of projection bases are small, so that the signaling overhead of reporting all other groups of projection bases is relatively small.

[0133] Method 3: The projection bases included in some of the M groups of projection bases are selected from the projection bases included in the f-th group of projection bases, and the projection bases included in another group of projection bases are selected from the entire set of projection bases. Taking the e-th and g-th groups of projection bases in the M groups of projection bases as an example, the projection bases included in the e-th group of projection bases are selected from the projection bases included in the f-th group of projection bases. The f-th group of projection bases is the group of projection bases with the largest number of projection bases among the M groups of projection bases. The projection bases included in the g-th group of projection bases are selected from the set of projection bases. e, f, and g are integers greater than 1 and less than or equal to M, and e, f, and g are different.

[0134] In one exemplary embodiment, Figure 7 As shown, the full set of projection bases includes projection bases 1 to projection bases 9, and the terminal device selects a first group of projection bases from projection bases 1 to projection bases 9: projection bases 1 to projection bases 5; selects the remaining groups of projection bases from projection bases 1 to projection bases 5, for example, a second group of projection bases from projection bases 1 to projection bases 5: projection base 2, projection base 3, and projection base 4; and selects a third group of projection bases from projection bases 1 to projection bases 9: projection base 6 and projection base 7.

[0135] In the above three methods of determining M sets of projection bases, the projection base set may be agreed upon by a protocol or configured by a network device through signaling.

[0136] It should be understood that the projection substrate set includes multiple projection substrates, and the multiple projection substrates can be mutually orthogonal or non-orthogonal. The number of projection substrates included in each group of projection substrates in the M groups of projection substrates is less than or equal to the number of projection substrates included in the projection substrate set.

[0137] As an optional embodiment, the first basis is a spatial domain basis, a frequency domain basis, or a space-frequency domain basis, or the first basis includes a spatial domain basis and a frequency domain basis.

[0138] It should be understood that when the first basis includes a frequency domain basis and a spatial domain basis, the spatial domain basis and the frequency domain basis can be reported separately according to method 300, and this application does not make any specific limitations on this.

[0139] In a possible embodiment, when the projection basis set includes multiple projection bases that are mutually orthogonal, the first basis can satisfy any of the following: if the first basis is a spatial basis, then the multiple projection bases in the projection basis set can be 2-dimensional (dimensionality, D)-discrete Fourier transform (discrete fourier transform, DFT) vectors; or, if the first basis is a frequency domain basis, then the multiple projection bases in the projection basis set can be 1D-DFT vectors; or, if the first basis is a spatial-frequency domain basis, then the multiple projection bases in the projection basis set can be Kronecker products of 2D-DFT vectors and 1D-DFT vectors.

[0140] In a possible implementation, when the projection basis set includes multiple projection bases that are orthogonal to each other, the K projection bases corresponding to the s-th group of first bases in the M groups of first bases can be determined by the following method: select K such that ‖d H ×ΔU t ‖The largest basis, where d is any basis in the projected basis set, d H is the conjugate transposed matrix of any basis in the projective basis set, ‖d H ×ΔU t ‖ represents d H and ΔU t The F-norm of the matrix obtained by multiplication.

[0141] In a possible embodiment, when the projection basis set includes multiple projection bases that are non-orthogonal, the first basis may satisfy any one of the following: if the first basis is a spatial basis, the projection basis set may be composed of oversampled 2D-DFT vectors; or, if the first basis is a frequency domain basis, the projection basis set may be composed of oversampled 1D-DFT vectors; or, if the first basis is a spatial-frequency domain basis, the projection basis set may be composed of the Kronecker product of the oversampled 2D-DFT vector and the oversampled 1D-DFT vector.

[0142] In a possible implementation, when the projection basis set includes multiple projection bases that are non-orthogonal, the K projection bases corresponding to the s-th group of first bases in the M groups of first bases can be determined in the following manner: the terminal device uses a matching pursuit or orthogonal matching pursuit algorithm to determine the K projection bases corresponding to the s-th group of first bases in the M groups of first bases from the projection basis set.

[0143] The following describes in detail the method for reporting the third indication information.

[0144] As an optional embodiment, the third indication information is reported in the form of a bit map or a combination number.

[0145] When reporting the third indication information via a bitmap, the number of bits in the third indication information equals the number of selectable projection substrates, and each bit in the third indication information corresponds one-to-one to an selectable projection substrate, with each bit used to indicate whether its corresponding projection substrate is selected. For example, assuming the selectable projection substrate set includes projection substrate 1, projection substrate 2, and projection substrate 3, the terminal device may use three bits to report the third indication information, assuming 1 indicates selection and 0 indicates non-selection. For example, if the reported third indication information is 110, this indicates that projection substrate 1 and projection substrate 2 are the selected projection substrates, i.e., the first group of projection substrates includes projection substrate 1 and projection substrate 2.

[0146] When the third indication information is reported using the number of combinations, the number of bits of the third indication information can be determined using the following formula: log2P, where P is the number of possible combinations of projection substrates included in each group of projection substrates. If the value obtained according to the formula is not an integer, the number of bits of the third indication information is determined as an integer that is larger than and closest to the value. Different combinations of the number of bits of the third indication information indicate different combinations of projection substrates. In this way, the network device can determine the projection substrates included in each group of projection substrates based on the third indication information corresponding to each group of projection substrates. For example, assuming that the full set of projection substrates includes projection substrate 1, projection substrate 2, projection substrate 3, and projection substrate 4, and the number of projection substrates included in the first group of projection substrates is 3, there are 4 possible combinations of the projection substrates included in the first group of projection substrates. The above formula can determine that the terminal device needs to report this group of projection substrates using 2 bits. Assume that the correspondence between possible 2-bit combinations and projection base combinations is as follows: 11 corresponds to projection base 1, projection base 2, and projection base 3; 10 corresponds to projection base 1, projection base 2, and projection base 4; 01 corresponds to projection base 1, projection base 3, and projection base 4; and 00 corresponds to projection base 2, projection base 3, and projection base 4. If the first projection base group reported by the terminal device is 11, it means that the first projection base group includes projection base 1, projection base 2, and projection base 3.

[0147] The following describes in detail three methods for determining M itself and the number of first substrates included in each group of M groups of first substrates.

[0148] As an optional embodiment, M is agreed upon by the protocol or configured by the network device through signaling.

[0149] It should be understood that M is agreed upon in the protocol or configured by the network device through signaling, which can be understood as M itself being agreed upon in the protocol or configured by the network device through signaling. For example, M may be 2 or 3 as agreed upon in the protocol.

[0150] In mode 1, the number of first substrates included in each group of the M groups of first substrates is configured by the network device through signaling.

[0151] In an example, assuming that M is 2, the network device configures, through signaling, that the number of first substrates included in the first group of first substrates is 2, and the number of first substrates included in the second group of first substrates is 3.

[0152] In mode 2, the number of first substrates included in each of the M-1 groups of first substrates in the N and M groups of first substrates is configured by the network device through signaling.

[0153] It should be understood that, given N configured via signaling and the number of first substrates included in each of the M-1 groups of first substrates within the M groups of first substrates, the number of first substrates included in the remaining group of first substrates within the M groups of first substrates, excluding the M-1 group of first substrates, can be determined. This reduces signaling overhead compared to configuring the number of first substrates included in each of the M groups of first substrates via signaling by the network device. For example, assuming that the network device configures N as 10 and M as 3 to the terminal device via signaling, and that one of the three groups of first substrates includes 5 first substrates and the other includes 3 first substrates, the terminal device can determine that the remaining group of first substrates includes 2 first substrates.

[0154] In mode 3, the ratio of the number of first substrates included in each of the M-1 groups of first substrates in the N and M groups of first substrates to N is configured by the network device through signaling.

[0155] It should be understood that the terminal device can calculate the number of first bases included in each of the M-1 groups of first bases using the ratio of the number of first bases included in each of the N and M-1 groups of first bases to N, and calculate the number of first bases included in the remaining group of first bases in the M groups of first bases, excluding the M-1 group of first bases, based on the number of first bases included in each of the M-1 groups of first bases and N. In this way, compared to the network device configuring the number of first bases included in each of the M groups of first bases via signaling, the signaling overhead is reduced. For example, assuming that the network device configures N as 10 and M as 3 to the terminal device via signaling, and that the ratio of the number of first bases included in the first group of first bases to N is 1 / 2, and the ratio of the number of first bases included in the second group of first bases to N is 3 / 10, the terminal device can determine that the number of first bases included in the first group of first bases is 5 and the number of first bases included in the second group of first bases is 3. Therefore, the number of first bases included in the remaining group of first bases is calculated as 2 based on 10-5-3.

[0156] In the above-mentioned methods 1 to 3, the M-1 group of first substrates is the first M-1 group of first substrates or the last M-1 group of first substrates among the M groups of first substrates.

[0157] It should be understood that the first M-1 groups of first bases or the last M-1 groups of first bases can be understood as the first M-1 groups of first bases or the last M-1 groups of first bases in the M groups of first base sequence obtained after the terminal device sorts the M groups of first bases according to a certain sorting rule.

[0158] In one possible implementation, the terminal device sorts the M groups of first bases in ascending order of eigenvalues ​​or in descending order of eigenvalues. Taking the example of sorting the M groups of first bases in ascending order of eigenvalues, the first M-1 groups of first bases are the first M-1 groups of first bases in the sequence of M groups of first bases obtained by sorting the M groups of first bases in ascending order of eigenvalues; and the last M-1 groups of first bases are the last M-1 groups of first bases in the sequence of M groups of first bases obtained by sorting the M groups of first bases in ascending order of eigenvalues.

[0159] Exemplarily, assuming that M is 3, the three groups of first bases are the first group of first bases, the second group of first bases, and the third group of first bases. The terminal device can sort the three groups of first bases in ascending order of eigenvalue. When the eigenvalue of the first base with the smallest eigenvalue in the first group of first bases is greater than the eigenvalue of the first base with the largest eigenvalue in the third group of first bases, and the eigenvalue of the first base with the smallest eigenvalue in the third group of first bases is greater than the eigenvalue of the first base with the largest eigenvalue in the second group of first bases, the terminal device obtains the three groups of first base sequences after sorting the three groups of first bases as: the second group of first bases, the third group of first bases, and the first group of first bases. Then the first M-1 groups of first bases represent the second group of first bases and the third group of first bases, and the last M-1 groups of first bases represent the third group of first bases and the first group of first bases.

[0160] As an optional embodiment, the group identifier of the M-1 group of first bases is agreed upon by protocol.

[0161] It should be understood that the group identifier can be understood as information used to indicate each group of first bases, and can also be called a group index, a group serial number, etc. This application does not make specific limitations on this.

[0162] In a specific example, the group identifiers of the M groups of bases are 1 to M respectively, then the protocol can stipulate that the group identifiers of the above-mentioned M-1 group of first bases are 1 to M-1, 2 to M, or 1, 3 to M, etc., among which 1, 3 to M can indicate that the M-1 group of first bases is the first group of first bases in the M groups of first bases, and the third group of first bases to the Mth group of first bases.

[0163] Two methods for determining the number of projection substrates included in each group of M groups of projection substrates are described in detail below.

[0164] In a first manner, the number of projection bases included in each group of M groups of projection bases is configured by the network device through signaling.

[0165] For example, assuming that M is 2, the network device may configure, through signaling, the number of projection substrates included in the first group of projection substrates to be 5, and the number of projection substrates included in the second group of projection substrates to be 7. The terminal device may then determine, based on the numbers of projection substrates included in the two groups of projection substrates configured through signaling by the network device, that the number of projection substrates corresponding to one of the two groups of first substrates is 5, and the number of projection substrates corresponding to the other first substrate is 7.

[0166] In the second method, the ratio of the number K of projection bases included in the sth group of projection bases in the M groups of projection bases and the number of projection bases included in each group of projection bases in the remaining groups of projection bases in the M groups of projection bases except the sth group of projection bases to K is configured by the network device through signaling, s is an integer greater than or equal to 1 and less than or equal to M, and K is an integer greater than 0.

[0167] For example, when M is 2 and s is 1, assuming that the network device configures through signaling that the number of projection substrates included in the first group of projection substrates is 10, and the ratio of the number of projection substrates included in the second group of projection substrates to the number of projection substrates included in the first group of projection substrates is 1 / 2, then the terminal device can determine that the number of projection substrates included in the second projection substrate is 5.

[0168] In the second manner described above, optionally, the sth group of projection bases is the first group of projection bases or the last group of projection bases among the M groups of projection bases.

[0169] It should be understood that the first group of projection bases or the last group of projection bases may be the first group of projection bases or the last group of projection bases in a sequence of M groups of projection bases obtained after the terminal device sorts the M groups of projection bases. For example, the terminal device may sort the projection bases according to the number of projection bases included in each group, for example, sorting them in ascending order of the number of projection bases. In this case, the first group of projection bases is the group including the largest number of projection bases, and the last group of projection bases is the group including the smallest number of projection bases.

[0170] Optionally, the group identifier of the sth group of projection bases can be agreed upon through a protocol. For example, assuming that the group identifiers of the M groups of projection bases are Z1 to Z M Then we can agree that the projection basis of the s group is Z1, Z M When the protocol stipulates that the sth group of projection bases is Z1, the terminal device can determine that the sth group of projection bases is the first group of projection bases according to Z1.

[0171] The following describes a method for processing the first projection coefficient and the second projection coefficient before the terminal device reports the first projection coefficient and the second projection coefficient.

[0172] As an optional embodiment, the first amplitude normalized value of the first projection coefficient corresponding to the i-th first basis among the N first basis is the maximum amplitude value among the first projection coefficients corresponding to the i-th first basis, and the second amplitude normalized value of the second projection coefficient corresponding to the i-th first basis is the maximum amplitude value among the second projection coefficients corresponding to the i-th first basis, where i is an integer greater than or equal to 1 and less than or equal to N; the first CSI also includes fourth indication information, and the fourth indication information is used to indicate the ratio of the first amplitude normalized value to the second amplitude normalized value.

[0173] It should be understood that the first projection coefficients include coefficients corresponding to each of the N first bases. For example, the i-th column of the first projection coefficients may be the first projection coefficients corresponding to the i-th first base among the N first bases.

[0174] The terminal device usually normalizes the first projection coefficient and the second projection coefficient first, and then quantizes the amplitude and phase and reports them separately. Since the first basis changes slowly over time, the N first basis that the terminal device needs to report at time t can be The linear combination of the N first bases is more accurately represented, so that most of the information of the N first bases is included in the first projection coefficient, resulting in a large difference in amplitude between the first projection coefficient corresponding to the i-th first base and the second projection coefficient corresponding to the i-th first base for the i-th first base in the N first bases. Therefore, the terminal device can use different amplitude normalization values ​​to normalize the first projection coefficient corresponding to the i-th first base and the second projection coefficient corresponding to the i-th first base, respectively. In this way, compared with using the same amplitude normalization value to normalize the first projection coefficient corresponding to the i-th first base and the second projection coefficient corresponding to the i-th first base, it helps to improve the accuracy of reporting the first projection coefficient and the second projection coefficient.

[0175] In addition, since the first projection coefficient and the second projection coefficient received by the network device are normalized using different amplitude normalization values, the terminal device also needs to report the ratio between the first amplitude normalization value corresponding to the first projection coefficient corresponding to the i-th first basis and the second amplitude corresponding to the second projection coefficient corresponding to the i-th first basis. In this way, the network device can restore the normalized first and second projection coefficients to their original proportional state based on this ratio. For example, assuming that the first amplitude normalization value is 100 and the second amplitude normalization value is 10, then assuming that the first coefficient in the i-th column of the first projection coefficient before normalization is 90 and the second coefficient in the i-th column of the second projection coefficient before normalization is 9, that is, the ratio of the first coefficient to the second coefficient in the initial state is 10; however, after normalization, the first coefficient and the second coefficient are both 0.9, and the ratio of the first coefficient to the second coefficient is 1. Therefore, the network device needs to restore the ratio of the first coefficient to the second coefficient to its initial state based on the ratio between the first amplitude normalization value corresponding to the first projection coefficient and the second amplitude corresponding to the second projection coefficient.

[0176] It should be understood that the above technical solution uses the first projection coefficient corresponding to the i-th first substrate and the second projection coefficient corresponding to the i-th first substrate as an example to illustrate the normalization processing method for the first projection coefficient corresponding to the i-th first substrate and the second projection coefficient corresponding to the i-th first substrate before reporting. For first substrates other than the i-th first substrate among the N first substrates, the first projection coefficient and the second projection coefficient corresponding to each first substrate can also be normalized in the same manner, and this application does not specifically limit this.

[0177] As an optional embodiment, the amplitude quantization bits of the first projection coefficient and / or the amplitude quantization bits of the second projection coefficient are configured by the network device through signaling.

[0178] In one possible implementation, the amplitude quantization bit of the first projection coefficient and the amplitude quantization bit of the second projection coefficient may be the same or different; when the amplitude quantization bit of the first projection coefficient and the amplitude quantization bit of the second projection coefficient are the same, the network device configures the amplitude quantization bit of the first projection coefficient or the amplitude quantization bit of the second projection coefficient through signaling.

[0179] The present application also provides another method for reporting channel state information, which can improve the accuracy of reporting the first projection coefficient and the second projection coefficient.

[0180] A method for reporting channel state information, comprising the following steps: receiving a reference signal from a network device; performing channel measurement based on the reference signal, and sending first CSI to the network device; wherein the first CSI includes first indication information, second indication information, third indication information, and fourth indication information, the first indication information being used to indicate a first projection coefficient, the second indication information being used to indicate a second projection coefficient, the third indication information being used to indicate each projection basis in M ​​groups of projection bases, the M groups of projection bases corresponding to M groups of first bases, the projection bases included in any two groups of projection bases in the M groups of projection bases being not completely the same, the first projection coefficient, the second projection coefficient, and the M groups of projection bases being used to determine the M groups of first bases , M groups of first bases are obtained by dividing N first bases, and the fourth indication information is used to indicate the ratio of the first amplitude normalized value of the first projection coefficient corresponding to the i-th first basis in the N first bases to the second amplitude normalized value of the second projection coefficient corresponding to the i-th first basis in the N first bases, the first amplitude normalized value is the maximum amplitude among the first projection coefficients corresponding to the i-th first basis, and the second amplitude normalized value is the maximum amplitude among the second projection coefficients corresponding to the i-th first basis, i is an integer greater than or equal to 1 and less than or equal to N, N is a positive integer greater than 1, M is an integer greater than 1 and less than N, and the first basis is used to determine the precoding matrix indication PMI or the channel covariance matrix.

[0181] It should be understood that the first basis is a spatial basis, a frequency domain basis or a space-frequency domain basis, or the first basis includes a spatial basis and a frequency domain basis. The channel covariance matrix is ​​the spatial covariance matrix of the channel, the frequency domain covariance matrix of the channel or the space-frequency domain joint covariance matrix of the channel, or the channel covariance matrix includes the spatial covariance matrix of the channel and the frequency domain covariance matrix of the channel. The covariance matrix can be used for channel estimation of uplink pilot signals by network equipment in a TDD system. For example, based on the spatial covariance matrix of the channel, minimum mean square error estimation of the spatial channel can be performed to improve the accuracy of channel estimation.

[0182] In one possible scenario, although the uplink and downlink channels of the TDD system are reciprocal and the network equipment can obtain downlink channel state information based on the uplink pilot signal, for some cell edge users, due to the limited transmission power of the terminal device, the uplink pilot signal signal-to-noise ratio on the network device side is low, and the accuracy of the downlink channel state information directly obtained using the uplink pilot signal is low. To solve this technical problem, the terminal device can report CSI, which can be used to determine channel covariance information, that is, the channel covariance matrix. Then, the network device can obtain more accurate channel state information in combination with the uplink pilot signal, and then determine the precoding of data transmission.

[0183] As an optional embodiment, the amplitude quantization bits of the first projection coefficient and / or the amplitude quantization bits of the second projection coefficient are configured by the network device through signaling.

[0184] In one possible implementation, the amplitude quantization bit of the first projection coefficient and the amplitude quantization bit of the second projection coefficient may be the same or different; when the amplitude quantization bit of the first projection coefficient and the amplitude quantization bit of the second projection coefficient are the same, the network device configures the amplitude quantization bit of the first projection coefficient or the amplitude quantization bit of the second projection coefficient through signaling.

[0185] It should be understood that the order of execution of the above methods does not necessarily mean the order in which they are executed. The order in which each process is executed should be determined by its function and internal logic.

[0186] Combined with the above Figures 1 to 7 , describes in detail the CSI reporting method of the embodiment of the present application, and the following is combined with Figure 8 and Figure 9 , a detailed description of the CSI reporting apparatus according to an embodiment of the present application is provided. The CSI reporting apparatus includes modules or units for executing each of the corresponding parts of the above-described embodiments. These modules or units may be software, hardware, or a combination of software and hardware. The following only briefly illustrates the information transmission apparatus. For implementation details, please refer to the description of the aforementioned method embodiment and will not be repeated here.

[0187] Figure 8 Schematic block diagram of a CSI reporting device 800 provided in an embodiment of the present application. Figure 8 As shown, the apparatus 800 includes: a receiving module 801 and a sending module 802 .

[0188] A receiving module 801 is used to receive a reference signal from a network device; a sending module 802 is used to perform channel measurement based on the reference signal and send a first CSI to the network device; wherein the first CSI includes first indication information, second indication information and third indication information, the first indication information is used to indicate a first projection coefficient, the second indication information is used to indicate a second projection coefficient, and the third indication information is used to indicate each group of projection bases in M ​​groups of projection bases, the M groups of projection bases correspond to M groups of first bases, and the projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same, the first projection coefficient, the second projection coefficient and the M groups of projection bases are used to determine the M groups of first bases, the first base is used to determine the precoding matrix indication PMI, and M is an integer greater than 1.

[0189] Optionally, M groups of first bases are obtained by dividing N first bases according to the size of their eigenvalues, and in the M groups of first bases, the eigenvalue of the first base with the smallest eigenvalue in the p-th group of first bases is greater than the eigenvalue of the first base with the largest eigenvalue in the q-th group of first bases, the number of projection bases in the p-th group of projection bases corresponding to the p-th group of first bases is less than the number of projection bases in the q-th group of projection bases corresponding to the q-th group of first bases, p and q are different, p and q are integers greater than or equal to 1 and less than or equal to M, and N is an integer greater than 1.

[0190] Optionally, the first projection coefficient is determined based on a first basis and a second basis, the second basis is reported through a second CSI, and the second CSI is reported before the first CSI; and / or, the second projection coefficient is determined based on M groups of projection basis, the first projection coefficient, the first basis, and the second basis.

[0191] Optionally, M is agreed upon by a protocol or configured by the network device through signaling.

[0192] Optionally, the number of first substrates included in each group of the M groups of first substrates is configured by the network device through signaling.

[0193] Optionally, the number of first substrates included in each of the M-1 groups of first substrates in the N and M groups of first substrates is configured by the network device through signaling.

[0194] Optionally, the ratio of the number of first substrates included in each of the M-1 groups of first substrates in the N and M groups of first substrates to N is configured by the network device through signaling.

[0195] Optionally, the M-1 group of first substrates is the front M-1 group of first substrates or the rear M-1 group of first substrates in the M group of first substrates.

[0196] Optionally, the group identifier of the M-1 group of first bases is agreed upon by protocol.

[0197] Optionally, the number of projection bases included in each group of projection bases in the M groups of projection bases is configured by the network device through signaling.

[0198] Optionally, the ratio of the number K of projection bases included in the sth group of projection bases in the M groups of projection bases and the number of projection bases included in each group of projection bases in the remaining groups of projection bases except the sth group of projection bases in the M groups of projection bases to K is configured by the network device through signaling, s is an integer greater than or equal to 1 and less than or equal to M, and K is an integer greater than 0.

[0199] Optionally, the sth group of projection bases is the first group of projection bases or the last group of projection bases among the M groups of projection bases.

[0200] Optionally, the projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from a projection base set, and e is an integer greater than 1 and less than or equal to M.

[0201] Optionally, the projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from the projection bases included in the f-th group of projection bases, the f-th group of projection bases is the group of projection bases including the largest number of projection bases in the M groups of projection bases, and f is an integer greater than 1 and less than or equal to M.

[0202] Optionally, the third indication information is reported in the form of a bit map or a combination number.

[0203] Optionally, the first amplitude normalized value of the first projection coefficient corresponding to the i-th first basis among the N first basis is the maximum amplitude value among the first projection coefficients corresponding to the i-th first basis, and the second amplitude normalized value of the second projection coefficient corresponding to the i-th first basis is the maximum amplitude value among the second projection coefficients corresponding to the i-th first basis, where i is an integer greater than or equal to 1 and less than or equal to N; the first CSI also includes fourth indication information, and the fourth indication information is used to indicate the ratio of the first amplitude normalized value to the second amplitude normalized value.

[0204] Optionally, the first basis is a spatial domain basis, a frequency domain basis, or a space-frequency domain basis, or the first basis includes a spatial domain basis and a frequency domain basis.

[0205] It should be understood that the device 800 here is embodied in the form of a functional module. The term "module" here can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 800 can be specifically the terminal device in the above embodiment, and the device 800 can be used to execute the various processes and / or steps corresponding to the terminal device in the above method embodiment. To avoid repetition, they will not be described here.

[0206] The apparatus 800 has the function of implementing the corresponding steps performed by the terminal device in the above method; the above functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0207] In the embodiments of this application, Figure 8 The device 800 may also be a chip, such as a SOC.

[0208] Figure 9 A schematic block diagram of a CSI reporting apparatus 900 provided in an embodiment of the present application is shown. The apparatus 900 includes a processor 901, a transceiver 902, and a memory 903. The processor 901, the transceiver 902, and the memory 903 communicate with each other via an internal connection path. The memory 903 is used to store instructions, and the processor 901 is used to execute the instructions stored in the memory 903 to control the transceiver 902 to send and / or receive signals.

[0209] It should be understood that the apparatus 900 can be specifically the terminal device in the above-mentioned embodiment, and can be used to execute the various steps and / or processes corresponding to the terminal device in the above-mentioned method embodiment. Optionally, the memory 903 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type. The processor 901 can be used to execute instructions stored in the memory, and when the processor 901 executes the instructions stored in the memory, the processor 901 is used to execute the various steps and / or processes of the above-mentioned method embodiment. The transceiver 902 may include a transmitter and a receiver. The transmitter can be used to implement the various steps and / or processes corresponding to the above-mentioned transceiver for performing the sending action, and the receiver can be used to implement the various steps and / or processes corresponding to the above-mentioned transceiver for performing the receiving action.

[0210] It should be understood that in the embodiments of the present application, the processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0211] During implementation, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0212] The present application also provides a computer-readable storage medium, which is used to store a computer program, and the computer program is used to implement the method shown in the above method embodiment.

[0213] The present application also provides a computer program product, which includes a computer program (also referred to as code or instructions). When the computer program runs on a computer, the computer can execute the method shown in the above method embodiment.

[0214] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0215] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0216] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the modules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0217] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected to achieve the purpose of the present embodiment according to actual needs.

[0218] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0219] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0220] The above description is merely a specific embodiment of the present application, but the scope of protection of the embodiments of the present application is not limited thereto. Any person skilled in the art can easily conceive of changes or substitutions within the technical scope disclosed in the embodiments of the present application, and such changes or substitutions should be included in the scope of protection of the embodiments of the present application. Therefore, the scope of protection of the embodiments of the present application should be based on the scope of protection of the claims.

Claims

1. A method for reporting channel state information CSI, characterized in that: include: receiving a reference signal from a network device; Perform channel measurement according to the reference signal, and send a first CSI to the network device; Among them, the first CSI includes first indication information, second indication information and third indication information, the first indication information is used to indicate the first projection coefficient, the second indication information is used to indicate the second projection coefficient, and the third indication information is used to indicate each group of projection bases in M ​​groups of projection bases, the M groups of projection bases correspond to M groups of first bases, and the projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same. The first projection coefficient, the second projection coefficient and the M groups of projection bases are used to determine the M groups of first bases, and the first base is used to determine the precoding matrix indication PMI, and M is an integer greater than 1.

2. The method according to claim 1, characterized in that The M groups of first basis are obtained by dividing the N first basis according to the size of their eigenvalues, wherein in the M groups of first basis, the eigenvalue of the first basis with the smallest eigenvalue in the p-th group of first basis is greater than the eigenvalue of the first basis with the largest eigenvalue in the q-th group of first basis, the number of projection basis in the p-th group of projection basis corresponding to the p-th group of first basis is less than the number of projection basis in the q-th group of projection basis corresponding to the q-th group of first basis, p and q are different, and p and q are integers greater than or equal to 1 and less than or equal to M, and N is an integer greater than 1.

3. The method according to claim 2, characterized in that The first projection coefficient is determined according to the first basis and a second basis, the second basis is reported through a second CSI, and the second CSI is reported before the first CSI; and / or, The second projection coefficient is determined based on the M groups of projection bases, the first projection coefficient, the first base and the second base.

4. The method according to claim 2 or 3, characterized in that: The M is agreed upon by the protocol or configured by the network device through signaling.

5. The method according to any one of claims 1 to 4, characterized in that The number of first substrates included in each group of the M groups of first substrates is configured by the network device through signaling.

6. The method according to any one of claims 2 to 4, characterized in that The number of first substrates included in each group of first substrates in the M-1 groups of first substrates in the N and M groups of first substrates is configured by the network device through signaling.

7. The method according to any one of claims 2 to 4, characterized in that The ratio of the number of first substrates included in each group of first substrates in the N and M-1 groups of first substrates in the M groups to N is configured by the network device through signaling.

8. The method according to claim 6 or 7, characterized in that: The M-1 group of first substrates is the front M-1 group of first substrates or the rear M-1 group of first substrates in the M group of first substrates.

9. The method according to any one of claims 6 to 8, characterized in that The group identifier of the first basis of the M-1 group is agreed upon by the protocol.

10. The method according to any one of claims 1 to 9, characterized in that The number of projection substrates included in each group of projection substrates in the M groups of projection substrates is configured by the network device through signaling.

11. The method according to any one of claims 1 to 9, characterized in that The ratio of the number K of projection bases included in the sth group of projection bases in the M groups of projection bases and the number of projection bases included in each group of projection bases in the remaining groups of projection bases in the M groups of projection bases except the sth group of projection bases to K is configured by the network device through signaling, s is an integer greater than or equal to 1 and less than or equal to M, and K is an integer greater than 0.

12. The method according to claim 11, characterized in that The sth group of projection substrates is the first group of projection substrates or the last group of projection substrates among the M groups of projection substrates.

13. The method according to any one of claims 1 to 12, characterized in that The projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from a projection base set, and e is an integer greater than 1 and less than or equal to M.

14. The method according to any one of claims 1 to 12, characterized in that The projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from the projection bases included in the f-th group of projection bases, and the f-th group of projection bases is a group of projection bases including the largest number of projection bases in the M groups of projection bases, and f is an integer greater than 1 and less than or equal to M.

15. The method according to any one of claims 1 to 14, characterized in that The third indication information is reported in the form of a bit map or a combination number.

16. The method according to any one of claims 1 to 15, characterized in that A first amplitude normalized value of the first projection coefficient corresponding to the ith first basis among the N first basis is the maximum amplitude value of the first projection coefficient corresponding to the ith first basis, and a second amplitude normalized value of the second projection coefficient corresponding to the ith first basis is the maximum amplitude value of the second projection coefficient corresponding to the ith first basis, where i is an integer greater than or equal to 1 and less than or equal to N; The first CSI also includes fourth indication information, where the fourth indication information is used to indicate a ratio between the first amplitude normalization value and the second amplitude normalization value.

17. The method according to any one of claims 1 to 16, characterized in that The first basis is a spatial domain basis, a frequency domain basis or a space-frequency domain basis, or the first basis includes a spatial domain basis and a frequency domain basis.

18. A channel state information (CSI) reporting device, characterized in that: include: A receiving module, used for receiving a reference signal from a network device; A sending module, configured to perform channel measurement according to the reference signal and send a first CSI to the network device; Among them, the first CSI includes first indication information, second indication information and third indication information, the first indication information is used to indicate the first projection coefficient, the second indication information is used to indicate the second projection coefficient, and the third indication information is used to indicate each group of projection bases in M ​​groups of projection bases, the M groups of projection bases correspond to M groups of first bases, and the projection bases included in any two groups of projection bases in the M groups of projection bases are not exactly the same. The first projection coefficient, the second projection coefficient and the M groups of projection bases are used to determine the M groups of first bases, and the first base is used to determine the precoding matrix indication PMI, and M is an integer greater than 1.

19. The device according to claim 18, characterized in that The M groups of first basis are obtained by dividing the N first basis according to the size of their eigenvalues, wherein in the M groups of first basis, the eigenvalue of the first basis with the smallest eigenvalue in the p-th group of first basis is greater than the eigenvalue of the first basis with the largest eigenvalue in the q-th group of first basis, the number of projection basis in the p-th group of projection basis corresponding to the p-th group of first basis is less than the number of projection basis in the q-th group of projection basis corresponding to the q-th group of first basis, p and q are different, and p and q are integers greater than or equal to 1 and less than or equal to M, and N is an integer greater than 1.

20. The device according to claim 19, characterized in that The number of first substrates included in each group of the M groups of first substrates is configured by the network device through signaling.

21. The device according to any one of claims 19 to 20, characterized in that The number of first substrates included in each group of first substrates in the M-1 groups of first substrates in the N and M groups of first substrates is configured by the network device through signaling.

22. The device according to any one of claims 19 to 20, characterized in that The ratio of the number of first substrates included in each group of first substrates in the N and M-1 groups of first substrates in the M groups to N is configured by the network device through signaling.

23. The device according to any one of claims 18 to 22, characterized in that The number of projection substrates included in each group of projection substrates in the M groups of projection substrates is configured by the network device through signaling.

24. The device according to any one of claims 18 to 22, characterized in that The ratio of the number K of projection bases included in the sth group of projection bases in the M groups of projection bases and the number of projection bases included in each group of projection bases in the remaining groups of projection bases in the M groups of projection bases except the sth group of projection bases to K is configured by the network device through signaling, s is an integer greater than or equal to 1 and less than or equal to M, and K is an integer greater than 0.

25. The device according to any one of claims 18 to 24, characterized in that The projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from a projection base set, and e is an integer greater than 1 and less than or equal to M.

26. The device according to any one of claims 18 to 24, characterized in that The projection bases included in the e-th group of projection bases in the M groups of projection bases are selected from the projection bases included in the f-th group of projection bases, and the f-th group of projection bases is a group of projection bases including the largest number of projection bases in the M groups of projection bases, and f is an integer greater than 1 and less than or equal to M.

27. The device according to any one of claims 18 to 26, characterized in that The first projection coefficient corresponds to a first amplitude normalized value, the second projection coefficient corresponds to a second amplitude normalized value, the first amplitude normalized value is the maximum amplitude value among the first projection coefficients, and the second amplitude normalized value is the maximum amplitude value among the second projection coefficients; The first CSI also includes fourth indication information, where the fourth indication information is used to indicate a ratio between the first amplitude normalization value and the second amplitude normalization value.

28. A channel state information (CSI) reporting device, characterized in that: include: A processor, wherein the processor is coupled to a memory, wherein the memory is used to store a computer program, and when the processor calls the computer program, the device executes the method according to any one of claims 1 to 17.

29. A computer-readable storage medium, characterized in that: Used to store a computer program, the computer program comprising instructions for implementing the method according to any one of claims 1 to 17.

30. A computer program product, comprising instructions, characterized in that: When the instructions are executed on a computer, the computer is caused to implement the method according to any one of claims 1 to 17.

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