Communication method, communication apparatus, and system

Abstract

Provided are a communication method, a communication apparatus, and a system, which can improve the spectral efficiency at the cost of a small amount of feedback overhead. The method comprises: a terminal receiving a first reference signal, wherein the first reference signal is transmitted on a reference channel and a target channel; on the basis of the first reference signal, determining a channel measurement result of the reference channel and a related parameter, wherein the channel measurement result of the reference channel comprises a CQI corresponding to each transmission layer among one or more transmission layers on the reference channel, the related parameter is used for indicating a relationship between a limiting spectral density function of the target channel and a limiting spectral density function of the reference channel, the limiting spectral density function of each channel is used for indicating a singular value corresponding to each transmission layer among one or more transmission layers on the channel, and the singular value corresponding to each transmission layer is used for determining the corresponding CQI; and sending first indication information, wherein the first indication information is used for indicating the channel measurement result of the reference channel and the related parameter.

Description

Communication method, communication device and system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 23, 2024, with application number 202410208246.1 and application name “Communication Method, Communication Device and System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of wireless communications, and in particular to a communication method, a communication device, and a system. Background Art

[0003] In multiple-input, multiple-output (MIMO) systems, channel quality feedback is crucial for network scheduling. For example, network devices can use the channel quality indication (CQI) to determine the modulation and coding scheme (MCS), precoding, and other strategies. Therefore, the higher the accuracy of the CQI fed back by the terminal, the more conducive it is to network device scheduling, thereby improving communication system performance and spectrum efficiency.

[0004] With the development of Massive MIMO technology, the number of antenna ports has increased, and spatial resources have become more abundant, thus supporting the scheduling of more transmission layers. Currently, the CQIs fed back by terminals are mainly codeword-level CQI and subband-level CQI. The codeword-level CQI is CQI in the spatial domain, and the subband-level CQI is CQI in the frequency domain. Currently, each codeword supports mapping of up to four transmission layers. Therefore, the codeword-level CQI can indicate the channel quality of up to four transmission layers. However, as the number of scheduled transmission layers and subbands increases, if CQI feedback is still based on this method, the feedback overhead will increase exponentially, affecting spectrum efficiency. Summary of the Invention

[0005] The present application provides a communication method, a communication device, and a system, in order to improve spectrum efficiency by reducing feedback overhead.

[0006] In a first aspect, a communication method is provided, which can be applied to a terminal side, such as a terminal or a communication module in a terminal, or a circuit or chip in a terminal responsible for a communication function (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or system in package (SIP) chip containing a modem core, etc.).

[0007] Taking the application of this method to a terminal as an example, in this method, the terminal receives a first reference signal, which is transmitted on a reference channel and a target channel; based on the received first reference signal, the terminal determines a channel measurement result and related parameters of the reference channel, the channel measurement result of the reference channel includes: a CQI corresponding to each transmission layer in one or more transmission layers on the reference channel, the related parameters are used to indicate the relationship between the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel, the limiting spectral density function of the reference channel is used to indicate the singular values ​​corresponding to each transmission layer in the one or more transmission layers on the reference channel, the limiting spectral density function of the target channel is used to indicate the singular values ​​corresponding to each transmission layer in the one or more transmission layers on the target channel, the singular values ​​corresponding to the first transmission layer are used to determine the CQI corresponding to the first transmission layer, and the first transmission layer is any one of the one or more transmission layers; first indication information is sent, and the first indication information is used to indicate the channel measurement result and the related parameters of the reference channel.

[0008] The first transmission layer is any one of one or more transmission layers. In other words, the singular value corresponding to the first transmission layer is used to determine the CQI corresponding to the first transmission layer. Alternatively, the singular value corresponding to each transmission layer is used to determine the CQI corresponding to each transmission layer.

[0009] The relationship between the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel may specifically refer to the relative relationship between the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel, or simply referred to as the relationship between the target channel and the reference channel.

[0010] The technical solution provided by this application utilizes the similarity of the extreme spectrum of large-scale random matrices, and indirectly indicates the CQI corresponding to each transmission layer on the target channel through the CQI corresponding to each transmission layer on the reference channel and the relevant parameters used to indicate the relationship between the reference channel and the target channel. Therefore, the terminal side indicates the channel measurement results and related parameters of the reference channel through a small amount of indication overhead, and the network side can obtain CQIs of the transmission layers corresponding to more channels, thereby providing richer channel state information for the scheduling of the network side, so that the network side can schedule more reasonably and improve spectrum efficiency. In other words, a small amount of feedback overhead is exchanged for the improvement of spectrum efficiency.

[0011] It should be noted that the first reference signal is transmitted on the reference channel and the target channel. This means that the transmission resources of the first reference signal may include the reference channel and the target channel. Transmission includes sending and receiving. The names of the reference channel and the target channel are simply for ease of distinction and do not limit the transmission of the first reference signal on two channels, nor do they limit the size of the transmission resources of the first reference signal. The transmission resources of the first reference signal can be divided in the frequency domain or in the time domain to obtain the reference channel and the target channel. When dividing in the frequency domain, the reference channel and the target channel can correspond to different frequency domain resources; when dividing in the time domain, the reference channel and the target channel can correspond to different time domain resources.

[0012] As long as the distance between the weighting coefficients corresponding to the extreme spectral density functions of the reference channel and the target channel does not exceed a preset threshold (such as the first preset threshold), it can be considered that there is similarity between the reference channel and the target channel, and the CQI corresponding to each transmission layer on the reference channel and related parameters can be used to estimate the CQI corresponding to each transmission layer on the target channel.

[0013] In combination with the first aspect, in some possible implementations of the first aspect, the reference channel and the target channel correspond to different frequency domain units in the transmission resources of the first reference signal, the reference channel is a channel corresponding to the reference frequency domain unit, the target channel is a channel corresponding to the target frequency domain unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a first preset threshold.

[0014] That is to say, by dividing the transmission resources of the first reference signal in the frequency domain, the channel corresponding to the reference frequency domain unit (i.e., the reference channel) and the channel corresponding to the target frequency domain unit (i.e., the target channel) can be obtained. The reference channel and the target channel can occupy different frequency domain resources and the same time domain resources. It should be understood that this application does not limit the number of reference frequency domain units and the number of target frequency domain units.

[0015] The limiting spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the limiting spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the limiting spectral density function is the weighting coefficient when the limiting spectral density function is represented by the weighted sum of multiple basis functions.

[0016] In other words, the limiting spectral density function of the reference channel is a weighted sum of multiple basis functions, and the limiting spectral density function of the target channel is also a weighted sum of the multiple basis functions. In other words, the multiple basis functions are common to the reference channel and the target channel.

[0017] By using a common basis function to obtain the weighting coefficients corresponding to the limiting spectral density functions of different channels, the differences between the weighting coefficients corresponding to the limiting spectral density functions of different channels can be used to characterize the differences between different channels. If this difference is represented by relevant parameters, the relative relationship between the limiting spectral density function of the above-mentioned target channel and the limiting spectral density function of the reference channel can be indicated.

[0018] Exemplarily, the determining of the channel measurement result of the reference channel and the related parameters of the reference channel and the target channel based on the received first reference signal includes: performing channel estimation on the reference channel and the target channel based on the received first reference signal to obtain the channel matrix of the reference channel and the channel matrix of the target channel; performing channel measurement on the reference channel to obtain the channel measurement result of the reference channel; determining the singular value range of the reference channel based on the channel matrix of the reference channel; determining the singular value range of the target channel based on the channel matrix of the target channel; The channel matrix and singular value range of the reference channel are used to obtain the limiting spectral density function of the reference channel; based on the channel matrix and singular value range of the target channel, the limiting spectral density function of the target channel is obtained; based on the limiting spectral density function of the reference channel, the limiting spectral density function of the target channel, and the multiple basis functions, the weighting coefficients corresponding to the limiting spectral density function of the reference channel and the weighting coefficients corresponding to the limiting spectral density function of the target channel are determined; according to the weighting coefficients of the limiting spectral density function of the reference channel and the weighting coefficients of the limiting spectral density function of the target channel, the relevant parameters are determined.

[0019] Optionally, the method also includes: receiving first configuration information, the first configuration information being used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit of each first frequency band, or multiple basis functions corresponding to each first frequency band; wherein, the first frequency band includes multiple frequency domain units, and among the multiple frequency domain units, the distance between the weighting coefficient corresponding to the extreme spectral density function of the channel of any frequency domain unit other than the reference frequency domain unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the first preset threshold.

[0020] By dividing multiple frequency domain units into one or more first frequency bands (or, one or more groups of frequency domain units), the terminal can feedback the channel measurement results of the reference channel for the channel corresponding to each first frequency band (or, each group of frequency domain units), as well as related parameters used to indicate the relationship between the target channel and the reference channel.

[0021] Furthermore, the method also includes: before receiving the first configuration information, the method also includes: receiving a second reference signal, the second reference signal is transmitted on multiple frequency domain units; based on the received second reference signal, determining the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units, the weighting coefficients corresponding to the extreme spectral density functions of the channels of the multiple frequency domain units are determined based on multiple common basis functions, and are used to determine the one or more first frequency bands; sending second indication information, the second indication information is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units.

[0022] The network side can obtain the weighting coefficients corresponding to the extreme spectral density functions of the channels of each frequency domain unit fed back by the terminal in advance through the second reference signal. In one or more first frequency bands obtained by dividing multiple frequency domain units based on the weighting coefficients corresponding to the extreme spectral density functions of the channels of each frequency domain unit, the distance between the weighting coefficients corresponding to the extreme spectral density functions of the channels of the target frequency domain unit in each first frequency band and the weighting coefficients corresponding to the extreme spectral density functions of the channels of the reference frequency domain unit is small, that is, the similarity of the channels is high. Therefore, the CQI corresponding to each transmission layer on the target channel obtained based on the CQI and related parameter estimation corresponding to each transmission layer on the reference channel is more accurate, which is conducive to more reasonable scheduling on the network side and improved spectrum efficiency.

[0023] In combination with the first aspect, in some possible implementations of the first aspect, the reference channel and the target channel correspond to different time units in the transmission resources of the first reference signal, the reference channel is a channel corresponding to the reference time unit, the target channel is a channel corresponding to the target time unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a second preset threshold.

[0024] That is to say, by dividing the transmission resources of the first reference signal in the time domain, the channel corresponding to the reference time unit (i.e., the reference channel) and the channel corresponding to the target time unit (i.e., the target channel) can be obtained. The reference channel and the target channel can occupy different time domain resources and the same frequency domain resources. It should be understood that this application does not limit the number of reference time units and the number of target time units.

[0025] The limiting spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the limiting spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the limiting spectral density function is the weighting coefficient when the limiting spectral density function is represented by the weighted sum of multiple basis functions.

[0026] For the relevant description of the limit spectral density functions of the reference channel and the target channel and their corresponding weighting coefficients, please refer to the above text and will not be repeated here.

[0027] Optionally, the method also includes: receiving second configuration information, the second configuration information being used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit of each feedback cycle, or multiple basis functions corresponding to each feedback cycle; wherein the feedback cycle of the CQI includes multiple time units, and among the multiple time units, the distance between the weighting coefficient corresponding to the extreme spectral density function of the frequency channel of any time unit other than the reference time unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the second preset threshold.

[0028] The second preset threshold may be the same as or different from the first preset threshold mentioned above, and the present application does not limit the sizes of the first preset threshold and the second preset threshold.

[0029] By dividing multiple time units into one or more feedback cycles, the terminal can feed back the channel measurement result of the reference channel and related parameters indicating the relationship between the target channel and the reference channel for the channel corresponding to each feedback cycle.

[0030] Furthermore, before receiving the second configuration information, the method also includes: receiving a third reference signal, wherein the third reference signal is transmitted over multiple time units; determining, based on the received third reference signal, a weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units, wherein the weighting coefficients corresponding to the extreme spectral density functions of the channels of the multiple time units are respectively determined based on multiple common basis functions and are used to determine one or more feedback cycles of the CQI; and sending a third indication information, wherein the third indication information is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units.

[0031] The network side can obtain in advance the weighting coefficients corresponding to the extreme spectral density functions of the channels of each time unit within the preset bandwidth fed back by the terminal through the third reference signal, and the CQI feedback cycle can be determined based on the weighting coefficients corresponding to the extreme spectral density functions of the channels of each time unit. In each feedback cycle of the CQI, the distance between the weighting coefficients corresponding to the extreme spectral density functions of the channels of the target time unit and the weighting coefficients corresponding to the extreme spectral density functions of the channels of the reference time unit is small, that is, the similarity of the channels is high. Therefore, the CQI corresponding to each transmission layer on the target channel obtained based on the CQI and related parameter estimates corresponding to each transmission layer on the reference channel is more accurate, which is conducive to more reasonable scheduling on the network side and improved spectrum efficiency.

[0032] On the second aspect, a communication method is provided, which can be applied to the network side, such as a network device or a communication module in a network device, or a circuit or chip responsible for the communication function in the network device (such as a modem chip, or a SoC chip or SIP chip containing a modem core).

[0033] Taking the application of this method to a network device as an example, in this method, the network device receives first indication information, where the first indication information is used to indicate a channel measurement result and related parameters of a reference channel, where the channel measurement result of the reference channel includes a CQI corresponding to each transmission layer in one or more transmission layers on the reference channel, and the related parameters are used to indicate the relationship between the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel, where the limiting spectral density function of the reference channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the reference channel, and the limiting spectral density function of the target channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the target channel, and the singular value corresponding to the first transmission layer is used to determine the CQI corresponding to the first transmission layer, where the first transmission layer is any one of the one or more transmission layers; and based on the channel measurement result of the reference channel and the related parameters, the CQI corresponding to each transmission layer in the one or more transmission layers on the target channel is determined.

[0034] The technical solution provided by this application utilizes the similarity of the extreme spectrum of large-scale random matrices, and indirectly indicates the CQI corresponding to each transmission layer on the target channel through the CQI corresponding to each transmission layer on the reference channel and the relevant parameters used to indicate the relationship between the reference channel and the target channel. Therefore, the terminal side indicates the channel measurement results and related parameters of the reference channel through a small amount of indication overhead, and the network side can obtain CQIs of the transmission layers corresponding to more channels, thereby providing richer channel state information for the scheduling of the network side, so that the network side can schedule more reasonably and improve spectrum efficiency. In other words, a small amount of feedback overhead is exchanged for the improvement of spectrum efficiency.

[0035] In combination with the second aspect, in some possible implementations of the second aspect, the reference channel and the target channel correspond to different frequency domain units in the transmission resources of the first reference signal, the reference channel is a channel corresponding to the reference frequency domain unit, the target channel is a channel corresponding to the target frequency domain unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a first preset threshold.

[0036] The limiting spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the limiting spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the limiting spectral density function is the weighting coefficient when the limiting spectral density function is represented by the weighted sum of multiple basis functions.

[0037] Optionally, the method also includes: sending first configuration information, the first configuration information being used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit of each first frequency band, or multiple basis functions corresponding to each first frequency band; wherein, the first frequency band includes multiple frequency domain units, and among the multiple frequency domain units, the distance between the weighting coefficient corresponding to the extreme spectral density function of the channel of any frequency domain unit other than the reference frequency domain unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the first preset threshold.

[0038] Furthermore, before sending the first configuration information, the method also includes: sending a second reference signal, which is transmitted on multiple frequency domain units; receiving second indication information, which is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units; and determining the one or more first frequency bands based on the second indication information.

[0039] In combination with the second aspect, in some possible implementations of the second aspect, the reference channel and the target channel correspond to different time units in the transmission resource of the first reference signal, the reference channel is a channel corresponding to the reference time unit, the target channel is a channel corresponding to the target time unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a second preset threshold; wherein, the extreme spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the extreme spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the extreme spectral density function is the weighting coefficient when the extreme spectral density function is represented by the weighted sum of multiple basis functions.

[0040] Optionally, the method also includes: sending second configuration information, the second configuration information being used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit of each feedback cycle, or multiple basis functions corresponding to each feedback cycle; wherein the feedback cycle of the CQI includes multiple time units, and among the multiple time units, the distance between the weighting coefficient corresponding to the extreme spectral density function of the frequency channel of any time unit other than the reference time unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the second preset threshold.

[0041] Optionally, before sending the second configuration information, the method also includes: sending a third reference signal, wherein the third reference signal is transmitted over multiple time units; receiving third indication information, wherein the third indication information is used to indicate a weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units; and determining one or more feedback cycles of the CQI based on the third indication information.

[0042] It should be understood that the technical solution of the second aspect corresponds to the technical solution of the first aspect. For a more detailed description of various possible implementations of the second aspect, please refer to the first aspect and will not be repeated here.

[0043] In combination with the first aspect or the second aspect, in a possible design, the relevant parameters include a weighting coefficient corresponding to the limiting spectral density function of the reference channel and a weighting coefficient corresponding to the limiting spectral density function of the target channel.

[0044] That is, the weighting coefficients corresponding to the limiting spectral density function of the reference channel and the limiting spectral density function of the target channel are fed back as relevant parameters.

[0045] In combination with the first aspect or the second aspect, in another possible design, the relevant parameters include a ratio corresponding to each transmission layer in the one or more transmission layers, and the ratio corresponding to the first transmission layer is the ratio of an initial estimated value of the singular value of the first transmission layer on the target channel to an initial estimated value of the singular value of the first transmission layer on the reference channel, the initial estimated value of the singular value is determined based on an order statistic, the order statistic of the reference channel is determined based on the singular value range, extreme spectral density function and extreme spectral distribution function of the reference channel, and the order statistic of the target channel is determined based on the singular value range, extreme spectral density function and extreme spectral distribution function of the target channel.

[0046] That is, based on the weighting coefficients corresponding to the limiting spectral density functions of the reference channel and the target channel, the initial estimated values ​​of the singular values ​​of each transmission layer on the reference channel and the target channel can be further determined, and the ratio of the two can be fed back as the relevant parameter.

[0047] On the third aspect, a communication method is provided, which can be applied to the terminal side, such as the terminal or the communication module in the terminal, or the circuit or chip responsible for the communication function in the terminal (such as a modem chip, or a SoC chip or SIP chip containing a modem core).

[0048] Taking the application of this method to a terminal as an example, in this method, the terminal performs channel estimation based on the received fourth reference signal to obtain a weighting coefficient corresponding to the extreme spectral density function of the channel, where the extreme spectral density function of the channel is the weighted sum of multiple basis functions, and the multiple basis functions are basis functions common to multiple terminal devices; and sends fourth indication information, where the fourth indication information is used to indicate the weighting coefficient.

[0049] In a fourth aspect, a communication method is provided, which can be applied to the network side, such as a network device or a communication module in a network device, or a circuit or chip responsible for the communication function in the network device (such as a modem chip, or a SoC chip or SIP chip containing a modem core).

[0050] Taking the application of this method to a network device as an example, in this method, the network device receives fourth indication information from multiple terminals, where the fourth indication information from the multiple terminals is used to indicate multiple sets of weighting coefficients obtained by estimating channels corresponding to the same time-frequency resources based on multiple common basis functions by the multiple terminals, and the set of weighting coefficients indicated by the fourth indication information from a first terminal among the multiple terminals and the multiple basis functions are used to represent the limiting spectral density function of the channel estimated by the first terminal, where the first terminal is one of the multiple terminals; based on the fourth indication information, candidate terminals for multi-user (MU) scheduling are determined.

[0051] It should be understood that the technical solution of the fourth aspect corresponds to the technical solution of the third aspect.

[0052] In the technical solutions provided in the third or fourth aspects, the network side can obtain the weighting coefficients corresponding to the channel matrix fed back by each terminal within its signal coverage range, and can then determine candidate terminals for MU scheduling based on the distances between the weighting coefficients corresponding to the multiple terminals. Since the greater the distance between the weighting coefficients, the less similar the channels are, that is, the terminals may be located in different locations or farther apart, and the interference is also smaller, which is conducive to reducing interference between multiple terminals sharing the same time-frequency resources. In addition, after the network device determines the candidate terminal set, it can further determine the terminals that can be used for MU scheduling from the candidate terminal set. That is, it is not necessary to determine the terminals that can be used for MU scheduling from all terminals within the signal coverage range of the network device. Therefore, the amount of calculation of the network device can be reduced and the processing complexity can be reduced.

[0053] In combination with the first to fourth aspects, in some possible implementations, the number of the multiple basis functions is 4.

[0054] Simulations show that a greater number of basis functions leads to a more accurate distribution of the estimated channel singular values ​​of the target channel. However, when the number of basis functions exceeds four, the gain is minimal, so using more basis functions is unnecessary.

[0055] In the fifth aspect, a communication device is provided, which has the functions of implementing the first or third aspect mentioned above. For example, the communication device includes a module or unit or means corresponding to the operations involved in the first or third aspect mentioned above. The module or unit or means can be implemented by software, or by hardware, or by a combination of software and hardware.

[0056] In a sixth aspect, a communication device is provided, comprising one or more processors, wherein the one or more processors can execute a computer program or instruction stored in a memory, and when the computer program or instruction is executed, the communication device implements the method in any possible design or implementation of the first or third aspect above.

[0057] In one possible design, the communication device may further include an interface circuit, wherein the processor is configured to communicate with other devices or components through the interface circuit.

[0058] In one possible design, the communication device may further include the memory.

[0059] The communication device may be a terminal, or a communication module in a terminal, or a chip in the terminal responsible for communication functions such as a modem chip (also known as a baseband chip) or a SoC or SIP chip including a modem module.

[0060] In the seventh aspect, a communication device is provided, which has the functions of implementing the second or fourth aspect above. For example, the communication device includes a module or unit or means corresponding to the operations involved in the second or fourth aspect above. The module or unit or means can be implemented by software, or by hardware, or by a combination of software and hardware.

[0061] In an eighth aspect, a communication device is provided, comprising one or more processors. The one or more processors are capable of executing a computer program or instructions stored in a memory, and when the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the second or fourth aspect.

[0062] In one possible design, the communication device may further include an interface circuit, wherein the processor is configured to communicate with other devices or components through the interface circuit.

[0063] In one possible design, the communication device may further include the memory.

[0064] The above-mentioned communication device may be a network device, or a component in a network device (such as a circuit, a chip or a chip system, etc.).

[0065] In a ninth aspect, a communication system is provided, comprising the aforementioned terminal and network device. The terminal may be configured to execute the method in any possible design or implementation of the first aspect, and the network device may be configured to execute the method in any possible design or implementation of the second aspect; alternatively, the terminal may be configured to execute the method in any possible design or implementation of the third aspect, and the network device may be configured to execute the method in any possible design or implementation of the fourth aspect.

[0066] In the tenth aspect, the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When a computer reads and executes the computer-readable instructions, the computer executes the method in any possible design of the first to fourth aspects above.

[0067] In an eleventh aspect, the present application provides a computer program product, which, when read and executed by a computer, enables the computer to execute the method in any possible design of the first to fourth aspects above.

[0068] It should be understood that the fifth to eleventh aspects of the present application correspond to the technical solutions of the first to fourth aspects of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] FIG1 is a schematic diagram of a communication system applicable to the communication method provided in an embodiment of the present application;

[0070] FIG2 is a schematic flow chart of a communication method provided in an embodiment of the present application;

[0071] FIG3 is a schematic diagram of a channel singular value distribution curve provided in an embodiment of the present application;

[0072] FIG4 is a schematic diagram of a communication method provided by an embodiment of the present application from the perspective of a channel singular value distribution curve;

[0073] FIG5 is a schematic diagram illustrating the difference between weighting coefficients corresponding to channel matrices of different sub-bands provided in an embodiment of the present application;

[0074] FIG6 is a schematic diagram of a process that may be implemented before step 220 of method 200 according to an embodiment of the present application;

[0075] FIG7 is a schematic flowchart of determining a first frequency band according to an embodiment of the present application;

[0076] FIG8 is a schematic diagram of a first frequency band provided in an embodiment of the present application;

[0077] FIG9 is a schematic flow chart of a communication method provided in another embodiment of the present application;

[0078] FIG10 is a schematic diagram illustrating the difference between weighting coefficients corresponding to the channel matrix of the same subband at different transmission timing intervals (TTIs) provided by an embodiment of the present application;

[0079] FIG11 is a schematic flowchart of determining a CQI feedback cycle according to an embodiment of the present application;

[0080] FIG12 is a schematic diagram of a CQI feedback cycle provided in an embodiment of the present application;

[0081] FIG13 is a schematic diagram illustrating differences between weighting coefficients corresponding to channel matrices estimated by terminals at different locations according to an embodiment of the present application;

[0082] FIG14 is a schematic diagram showing the positions of different terminals from the perspective of network devices and terminals;

[0083] FIG15 is a schematic flow chart of a communication method provided in yet another embodiment of the present application;

[0084] FIG16 and FIG17 are schematic block diagrams of communication devices provided in embodiments of the present application;

[0085] FIG18 is a schematic diagram of the structure of a terminal provided in an embodiment of the present application;

[0086] Figure 19 is a structural diagram of the network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0087] The technical solution in this application will be described below with reference to the accompanying drawings.

[0088] The technical solutions provided in this application can be applied to various communication systems, such as: fifth generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, wireless local area networks (WLAN) systems, satellite communication systems, future communication systems, such as sixth generation (6G) mobile communication systems, or a fusion system of multiple systems. The technical solutions provided in this application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0089] A device in a communication system can send a signal to another device or receive a signal from another device. The signal may include information, signaling, or data, etc. The device may also be replaced by an entity, a network entity, a communication device, a communication module, a node, a communication node, etc. The present disclosure uses the device as an example for description. For example, the communication system may include at least one terminal device and at least one network device. The network device may send a downlink signal to the terminal device, and / or the terminal device may send an uplink signal to the network device. It is understandable that the terminal in the present disclosure may be replaced by a first communication device, and the network device may be replaced by a second communication device, and both perform the corresponding communication methods in the present disclosure.

[0090] Figure 1 is a schematic diagram of the architecture of a communication system applicable to the communication method provided in this application. Figure 1 shows a schematic diagram of a possible, non-limiting system architecture. As shown in Figure 1, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN 100 includes at least one RAN node (such as 110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal (such as 120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is connected to the RAN node 110 via a wireless connection. The RAN node 110 is connected to the core network 200 via a wireless or wired connection. The core network equipment in the core network 200 and the RAN node 110 in the RAN 100 can be different physical devices, or they can be the same physical device that integrates the core network logical functions and the radio access network logical functions.

[0091] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), such as a 4G or 5G mobile communication system, or a future-oriented evolutionary system (such as a 6G mobile communication system). The RAN 100 may also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (Wi-Fi) system. The RAN 100 may also be a communication system that integrates two or more of the above systems.

[0092] RAN node 110, sometimes also referred to as access network equipment, RAN entity, or access node, is a component of a communications system that facilitates wireless access for terminals and is a device or module with corresponding communication functions. RAN node 110 is typically equipped with a communication module, circuit, or chip that performs the corresponding communication functions. RAN node 110 may also be configured with program instructions for performing the corresponding communication functions and corresponding program instructions.

[0093] The multiple RAN nodes 110 in the communication system 10 can be nodes of the same type or different types. In some scenarios, the roles of the RAN nodes 110 and the terminals 120 are relative. For example, the network element 120i in Figure 1 can be a helicopter or a drone, which can be configured as a mobile base station. For the terminals 120j that access the RAN 100 through the network element 120i, the network element 120i is a base station; however, for the base station 110a, the network element 120i is a terminal. The RAN nodes 110 and the terminals 120 are sometimes referred to as communication devices. For example, the network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and the network elements 120a-120j can be understood as communication devices with terminal functions.

[0094] In one possible scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node may be a macro base station (such as 110a in Figure 1 ), a micro base station or an indoor station (such as 110b in Figure 1 ), a relay node or a donor node, or a wireless controller in a CRAN scenario. Alternatively, a RAN node may be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology may be a roadside unit (RSU).

[0095] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or they can be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0096] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called open CU (O-CU), DU may also be called open DU (O-DU), CU-CP may also be called open CU-CP (O-CU-CP), CU-UP may also be called open CU-UP (O-CU-UP), and RU may also be called open RU (O-RU). For the convenience of description, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0097] A terminal can be a device or module that accesses the above-mentioned communication system and has corresponding communication functions. A terminal can also be referred to as user equipment (UE), terminal, user device, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication device, user agent, or user device. The terminal is typically equipped with a communication module, circuit, or chip that performs the corresponding communication functions. The terminal is also configured with program instructions for performing the corresponding communication functions.

[0098] For example, the terminal in the embodiment of the present application can be a mobile phone, a personal digital assistant (PDA), a laptop computer, a tablet computer, a drone, a computer with wireless transceiver function, a machine-type communication (MTC) terminal, a virtual reality (VR) terminal, an augmented reality (AR) terminal, an Internet of Things (IoT) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home (such as a game console, a smart TV, a smart speaker, a smart refrigerator, and fitness equipment, etc.), a transport vehicle with wireless communication function, a communication module, and a roadside unit (RSU) with a terminal function.

[0099] In the embodiments of the present application, the terminal and network device can be hardware devices, or software functions running on dedicated hardware, software functions running on general-purpose hardware, such as virtualization functions instantiated on a platform (for example, a cloud platform), or entities including dedicated or general-purpose hardware devices and software functions. The present application does not limit the specific form of the terminal and network device.

[0100] In the embodiments of the present application, the functions of the RAN node may also be performed by a module (such as a chip) in the RAN node, or by a control subsystem that includes the RAN node functions. The control subsystem that includes the RAN node functions here may be a control center in the application scenarios of the above-mentioned terminals, such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal device may also be performed by a module (such as a chip) in the terminal device, or by a device that includes the terminal device functions. This application does not limit this.

[0101] It will be understood that FIG1 is only a simplified schematic diagram for ease of understanding, and the communication system may also include other possible devices, such as wireless relay devices and wireless backhaul devices. Each device may also include different functional units, which are not shown in FIG1 .

[0102] To facilitate understanding of the embodiments of the present application, several terms involved in this document are briefly explained below.

[0103] 1. Transport layer: This can also be referred to simply as a layer. A transport layer is the number of parallel data transmission paths between communication devices, such as the number of parallel data transmission paths between a terminal and a network device. The maximum number of transport layers can be the minimum of the number of transmit antennas and the number of receive antennas. Generally speaking, the maximum number of transport layers that each terminal can support is the rank of the channel matrix between the terminal and the network device. In other words, any number of transport layers can be scheduled for data transmission within the maximum number of transport layers supported by the channel. Therefore, the actual number of transport layers used ≤ the maximum number of transport layers = rank.

[0104] 2. Stream: This usually describes data, and the transmission of data is described as a data stream. In a MIMO system, the number of data streams is equal to the number of actual transmission layers.

[0105] 3. CQI: This indicator can be used to indicate channel quality. For example, in the case of downlink channel measurements, the terminal can measure the reference signal corresponding to the downlink channel and provide feedback to the network device regarding the CQI of the measured channel. Based on the CQI, the network device can select the appropriate scheduling algorithm, downlink data block size, and data rate to adapt to different wireless environments and ensure system performance.

[0106] The CQI is related to the signal to interference plus noise ratio (SINR) (also referred to as the signal to interference plus noise ratio) at the receiving end (e.g., the terminal). One possible design is that the CQI can correspond to the SINR, and a CQI value can represent a SINR value. In some cases, interference and noise can be considered as equivalent noise. In this case, the SINR can also be called the signal to noise ratio (SNR) (also referred to as the signal to noise ratio). In this case, the CQI can correspond to the SNR, and a CQI value can represent a SNR value.

[0107] To distinguish it from the subband-level CQI and the codeword-level CQI, the CQI corresponding to each transmission layer in one or more transmission layers is referred to as stream-level CQI or layer-level CQI in this document.

[0108] 4. Singular values: By performing singular value decomposition (SVD) on the channel matrix, we can obtain the singular values ​​of the channel matrix. The number of singular values ​​is also the rank of the channel matrix.

[0109] The singular values ​​obtained based on SVD can determine the power of the signal transmitted on each transmission layer. By measuring the power of the background noise, the SNR corresponding to each transmission layer can be calculated, and then the CQI corresponding to each transmission layer can be determined.

[0110] To facilitate understanding of the embodiments of the present application, the following points are first explained:

[0111] First, in this application, indications include explicit indications (also called direct indications) and implicit indications (also called indirect indications). Specifically, explicit indication information A refers to including information A; implicit indication information A refers to indicating information A through the correspondence between information A and information B and directly indicating information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured; or, it can also refer to indicating information A through information B and preset rules.

[0112] Second, in this application, information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, when information D is determined based on information E, and information E is determined based on information C.

[0113] Third, in this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship, but it does not exclude the situation where the previous and next associated objects are in an "and" relationship. The specific meaning can be understood in conjunction with the context. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, c can be single or multiple.

[0114] Fourth, in this application, prefixes such as "first" and "second" are used solely to distinguish between different items belonging to the same category and do not constrain the order, size, or quantity of the items. For example, "first information" and "second information" are simply different pieces of information; there is no temporal, size, or priority relationship between them.

[0115] Fifth, the communication between different devices involved in the embodiments of the present application may refer to direct communication between different devices (i.e., no other devices are required to transfer or forward), or may refer to communication between different devices through other devices (i.e., other devices are required to transfer or forward), or may refer to the functional unit inside the device communicating with other devices through another functional unit. That is to say, in this application, "sending information to... (terminal or network device)" can be understood as the destination end of the information being the terminal or network device, and may include sending information directly or indirectly to the terminal or network device. "Receiving information from... (terminal or network device)" can be understood as the source end of the information being the terminal or network device, and may include receiving information directly or indirectly from the terminal or network device. The information may be subjected to necessary processing between the source end and the destination end of the information transmission, such as format change, digital-to-analog conversion, amplification, filtering, etc., but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be repeated here.

[0116] Sixth, in the embodiments of the present application, "when", "if" and "if" all mean that the device will make corresponding processing under certain objective circumstances, which does not limit the time, and does not require the device to have a judgment action when it is implemented, nor does it mean that there are other limitations.

[0117] Seventh, in this application, words such as "example," "exemplarily," "for example," or "such as" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "example," "exemplarily," "for example," or "such as" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "example," "exemplarily," "for example," or "such as" is intended to present the relevant concepts in a concrete manner.

[0118] Eighth, in this application, for the convenience of distinction and explanation, the singular values ​​obtained by measurement are recorded as measured values, and the singular values ​​obtained by estimation are recorded as estimated values. Furthermore, the estimated values ​​can be divided into initial estimated values ​​and target estimated values. The initial estimated value is an estimated value obtained based on statistical estimation, which is often not accurate enough. The target estimated value is estimated based on the initial estimated value and the relationship between the reference subband and the target subband, which is more accurate than the initial estimated value.

[0119] Ninth, in this application, the results obtained by channel estimation can be expressed as a channel matrix, a channel vector, or other information that can be used to characterize the channel, and this application does not limit this. For ease of explanation, this document describes multiple embodiments using the channel matrix as an example, but this should not constitute any limitation on this application. This application does not limit the form in which the results obtained by channel estimation are expressed.

[0120] In addition, since the method provided in this application utilizes the similarity of the limiting spectra of large-scale random matrices, the channels mentioned in this article (such as reference channels, target channels, etc.) can all be represented by channel matrices. In the following text, "the limiting spectral density function of the channel" can specifically refer to "the limiting spectral density function of the channel matrix", and "the limiting spectral distribution function of the channel" can specifically refer to "the limiting spectral distribution function of the channel matrix". In some cases, "channel matrix" is referred to as "channel" just for the sake of simplicity.

[0121] Tenth, in this application, the network device may be a RAN device deployed with a CU, DU, and RU, or an ORAN device. To avoid repetition, the specific implementation of the sending or receiving operation involving the network device below is exemplified.

[0122] Exemplarily, in a RAN device deployed with CU, DU and RU, the specific implementation of the network device sending configuration information (such as the first to seventh configuration information shown below) can be: CU-CP generates configuration information and sends the configuration information through DU and RU; in an ORAN device, the specific implementation of the network device sending configuration information (such as the first to seventh configuration information shown below) can be: O-CU-CP generates configuration information and sends the configuration information through O-DU and O-RU.

[0123] For example, in a RAN device deployed with a CU, DU, and RU, the network device may transmit a reference signal (e.g., including the first to fourth reference signals shown below) by: the CU-CP generates the reference signal and transmits the reference signal through the DU and RU. In an ORAN device, the network device may transmit a reference signal (e.g., including the first to fourth reference signals shown below) by: the O-CU-CP generates the reference signal and transmits the reference signal through the O-DU and O-RU.

[0124] For example, in a RAN device deployed with a CU, DU, and RU, the specific implementation of the network device receiving indication information (e.g., including the first to third indication information shown below) may be: the RU receives the indication information and forwards the received indication information to the DU for processing. In an ORAN device, the specific implementation of the network device receiving indication information (e.g., including the first to third indication information shown below) may be: the O-RU receives the indication information and forwards the received indication information to the O-DU for processing.

[0125] In 5G NR and 6G, Massive MIMO, which significantly increases system capacity, will continue to be a key technology to meet high-speed transmission requirements. This technology leverages spatial resources to achieve array gain, multiplexing and diversity gain, and interference cancellation gain in space without increasing system bandwidth, exponentially increasing communication system capacity and spectral efficiency.

[0126] In a MIMO system, the number of transmission layers is related to the number of antennas. The number of transmission layers can be the minimum of the number of transmit and receive antennas. When the number of antenna ports is large, spatial resources are abundant, supporting the scheduling of more transmission layers. However, this also requires a larger amount of information for channel quality feedback or scheduling control. Compared to wideband channel state information, subband-level channel state information allows the network to perform more accurate precoding, thereby improving the SINR for each antenna port and ultimately improving system spectral efficiency. However, subband-level channel state information requires more signaling overhead. For example, in a frequency division duplex (FDD) system, if the number of scheduled transmission layers increases by one to two orders of magnitude and the number of subbands increases fivefold, assuming the current mapping rule of a maximum of four transmission layers to one codeword continues to be used, the subband-level CQI overhead reported by the terminal to the network equipment will increase by 50x to 500x. This will increase uplink resource overhead, ultimately affecting both uplink and downlink throughput. As the number of streams and bandwidth increase, the channel feedback overhead increases, impacting spectral efficiency.

[0127] Table 1 below shows several aspects of codewords and transport layer related content that have been agreed upon by the standard.

[0128] Table 1

[0129] The CQI overhead increases linearly with the number of subbands and antenna ports (or, the number of transmission layers and streams). When the bandwidth of Massive MIMO is large and the number of antenna ports is large, the feedback overhead also increases sharply.

[0130] In view of this, the present application provides a method that utilizes the similarity of the extreme spectrum of a large-scale random matrix, and indirectly indicates the CQI of each transmission layer on the target channel through the CQI of each transmission layer on the reference channel and the related parameters used to indicate the relationship between the reference channel and the target channel to be measured. Therefore, the terminal side indicates the channel measurement results and related parameters of the reference channel through a small amount of indication overhead, and the network side can obtain the CQI of the transmission layer corresponding to more channels. As a result, richer channel state information can be provided for the scheduling of network equipment, so that the network equipment can be scheduled more reasonably and the spectrum efficiency can be improved, that is, the spectrum efficiency can be improved in exchange for a small amount of feedback overhead.

[0131] For ease of distinction and explanation, the CQI corresponding to each transport layer is referred to herein as stream-level CQI. Stream-level CQI is simply a shorthand for distinguishing between subband-level CQI and codeword-level CQI and should not constitute any limitation for this application. For example, stream-level CQI may also be referred to as layer-level CQI, and so on, without limitation.

[0132] To facilitate understanding of the method provided in this application, the following first describes the process of estimating the stream-level CQI of the target channel based on the relationship between the reference channel and the target channel, and the stream-level CQI of the reference channel in combination with a specific algorithm; then describes the method provided in this application in combination with the process.

[0133] Exemplarily, based on the relationship between the reference channel and the target channel, and the stream-level CQI of the reference channel, the process of estimating the stream-level CQI of the target channel can be divided into the following three steps:

[0134] Step 1: Obtain weighting coefficients corresponding to the limiting spectral density functions of the channel matrix of the reference channel and the channel matrix of the target channel, respectively.

[0135] The channel matrix of the target channel and the channel matrix of the reference channel can be estimated based on the reference signal. The channel matrix of the target channel is recorded as H1, and the channel matrix of the reference channel is recorded as H2. It should be understood that the channel matrix H1 can be understood as the channel estimation result of the target channel, and the channel matrix H2 can be understood as the channel estimation result of the reference channel. The dimensions of the channel matrices H1 and H2 are both m×n, where m represents the number of receiving antennas and n represents the number of transmitting antennas. m and n are positive integers. Usually, the number of receiving antennas is less than or equal to the number of transmitting antennas, that is, The rank of the channel matrices H1 and H2 is R, where R is the minimum value of m and n.

[0136] First, based on existing algorithms, such as the moment passing method (MPM), the limiting spectral density (LSD) functions of the large-dimensional channel matrices H1 and H2 can be obtained, satisfying:

[0137] in, represents the limiting spectral density function of the channel matrix H1, represents the singular value in the limiting spectral density function of the channel matrix H1, Represents singular values The minimum value of Represents singular values The maximum value of represents the limiting spectral density function of the channel matrix H2, represents the singular value in the limiting spectral density function of the channel matrix H2, Represents singular values The minimum value of Represents singular values The maximum value of . It can be expressed that the singular values ​​of the channel matrix H1 are obtained The corresponding probability when It can be expressed that the singular values ​​of the channel matrix H2 are obtained The corresponding probability when . The singular value range of the channel matrix H1 is The minimum value among them and maximum value It can be obtained by performing singular value decomposition on the channel matrix H1; and the singular value range of the channel matrix H2 is The minimum value among them and maximum value It can be obtained by performing singular value decomposition on the channel matrix H2.

[0138] Secondly, for the limiting spectral density function and By integrating them separately, we can obtain the limiting spectral distribution functions of the large-dimensional channel matrices H1 and H2, which satisfy:

[0139] in, represents the limiting spectral distribution function of the channel matrix H1; represents the limiting spectral distribution function of the channel matrix H2; α k It represents the coefficient of the k-th term when solving the limiting spectral distribution function by the polynomial fitting method. k can take an integer value in the range of 0 to K-1, and K is the number of the above-mentioned multiple basis functions. It can be said that the singular values ​​of the channel matrix H1 are less than or equal to probability; It can be said that the singular values ​​of the channel matrix H2 are less than or equal to probability.

[0140] It should be noted that the limiting spectral distribution function and limiting spectral density function of the channel matrices H1 and H2 listed above can be understood as describing the distribution of the channel singular values ​​of H1 and H2 from a statistical perspective.

[0141] It can be understood that since the channel matrices H1 and H2 corresponding to different time-frequency resources are different, the range of singular values ​​is not necessarily the same, that is, and Not necessarily equal. and Therefore, the singular values ​​in different channel matrices can be replaced by variables. and Map to x' in the same range, x'∈(a,b). The details are as follows:

[0142] Then, the limiting spectral density functions of the channel matrices H1 and H2 are expressed as the weighted sum of multiple basis functions, as follows:

[0143] Where, f'(x')·(x') k is the kth basis function among the K basis functions, f'(x') satisfies η is a predefined parameter, and different channel matrices can choose the same value so that is the weighting coefficient corresponding to the kth basis function among the K weighting coefficients corresponding to the extreme spectral density function of the channel matrix H1; is the weighting coefficient corresponding to the kth basis function among the K weighting coefficients corresponding to the limiting spectral density function of the channel matrix H2.

[0144] The K basis functions are output by the statistical model. Based on the above K basis functions and the corresponding singular value ranges of the channel matrix H1, the limiting spectral density function of the channel matrix H1 represented by the weighted sum of the K basis functions can be obtained; based on the same K basis functions and the corresponding singular value ranges of the channel matrix H2, the limiting spectral density function of the channel matrix H2 represented by the weighted sum of the K basis functions can be obtained.

[0145] As can be seen, through variable substitution, the limiting spectral density functions of channel matrices H1 and H2 can be expressed as the weighted sum of multiple common basis functions. Because these multiple basis functions are common, the weighting coefficients of different channel matrices determine the specific values ​​of their limiting spectral distribution functions.

[0146] Optionally, K is 4. That is, there are four common basis functions, and the K weighting coefficients corresponding to the limiting spectral density function of the channel matrix of each channel are 4 weighting coefficients. K is defined as 4 because simulations have shown that a greater number of basis functions leads to a more accurate distribution of the estimated channel singular values ​​of the target channel. However, when the number of basis functions exceeds 4, that is, when K is greater than 4, the gain is minimal and is therefore unnecessary.

[0147] Step 2: Determine initial estimated values ​​of the singular values ​​of the channel matrix H1 and initial estimated values ​​of the singular values ​​of the channel matrix H2 based on the order statistics.

[0148] In step 1, by variable substitution, the limiting spectral density functions of the channel matrices H1 and H2 are expressed as a weighted sum of multiple common basis functions. The multiple common basis functions and the weighted coefficients corresponding to the limiting spectral densities of the channel matrices H1 and H2 are used to perform inverse variable substitution to map x' to the singular value range of the channel matrix H1. The channel matrix H1 can be obtained Limiting spectral density function within the range and the limiting spectral distribution function Map x' to the range of singular values ​​of the channel matrix H2 Then we can get the channel matrix H2 in Limiting spectral density function within the range and the limiting spectral distribution function

[0149] Limiting spectral density function based on channel matrix H1 and the limiting spectral distribution function And the limiting spectral density function of the channel matrix H2 and the limiting spectral distribution function Through Riemann summation, the order statistics of the r-th transmission layer of the channel matrices H1 and H2 can be obtained as follows:

[0150] Where r = 0, 1, ..., R-1.

[0151] Among them, order statistics is a statistical concept, which is obtained by arranging sample observations from small to large. represents the order statistic of the r-th transmission layer of the channel matrix H1; represents the order statistic of the r-th transmission layer of the channel matrix H2.

[0152] It should be understood that the order statistic is a statistic based on which specific singular values ​​can be obtained.

[0153] According to the order statistics of the r-th transmission layer of the channel matrices H1 and H2, the initial estimate of the r-th singular value can be obtained by variable substitution as follows:

[0154] in, represents the initial estimate of the rth singular value of the channel matrix H1, represents the initial estimate of the rth singular value of the channel matrix H2.

[0155] It is not difficult to see that the initial singular values ​​estimated above are all based on the extreme spectral distribution and extreme spectral density of the channel matrix of each sub-band, which is based on statistics and is therefore not accurate enough. However, the relative quantities between them are accurate, so their relative quantities and the measured values ​​of the singular values ​​of the reference sub-band can be used to estimate the singular values ​​of the target sub-band. or As relevant parameters to feedback.

[0156] Step 3: Using the measured values ​​of the singular values ​​of the r-th transmission layer of the reference subband, determine the target estimated values ​​of the singular values ​​of the r-th transmission layer of the target subband.

[0157] The measured values ​​of the singular values ​​of the rth transmission layer based on the reference subband, and the ratio or The target estimated value of the singular value of the r-th transmission layer of the target subband can be obtained. For the convenience of explanation, the singular value of the r-th transmission layer is referred to as the r-th singular value below.

[0158] Assume that the measured value of the rth singular value of the reference subband is recorded as Then the target estimate of the rth singular value of the target subband is satisfy It can be seen that the ratio or Any item in can determine the target estimated value of the rth singular value of the target subband.

[0159] Based on the above algorithm, the target estimated values ​​of the R singular values ​​corresponding to the R transmission layers of the target subband can be obtained, from which the CQI corresponding to the R transmission layers, ie, the stream-level CQI, can be further determined.

[0160] It should be understood that the above is only for facilitating understanding of how to obtain the stream-level CQI of the target subband, and does not limit the device for implementing the process.

[0161] The process of the method provided in this application will be described in detail below with reference to the accompanying drawings.

[0162] This document illustrates the method provided by the present application from the perspective of the interaction between the terminal side and the network side, in conjunction with the embodiments shown in multiple figures. However, this does not limit the embodiments of the present application in any way. The terminal side can be a terminal or a communication module in a terminal, or a circuit or chip in the terminal responsible for the communication function (such as a modem chip (also known as a baseband chip), or a SoC chip or SIP chip containing a modem core, etc.). The network side can be a network device or a component in a network device (such as a circuit, chip, or chip system, etc.).

[0163] In the multiple embodiments shown below, the reference channel and the target channel can be channels corresponding to frequency domain units, or channels corresponding to time units. When the reference channel and the target channel correspond to frequency domain units, the frequency domain unit can be divided into a reference frequency domain unit and a target frequency domain unit, corresponding to the reference channel and the target channel respectively; when the reference channel and the target channel correspond to time units, the time unit can be divided into a reference time unit and a target time unit, corresponding to the reference channel and the target channel respectively. Among them, a frequency domain unit can be one or more subbands, or one or more subcarriers, or one or more resource blocks (RB), or one or more resource block groups (RBG), etc., without limitation. A time unit can be one or more symbols, or one or more time slots, or one or more radio frames, etc., without limitation.

[0164] FIG2 is a schematic flow chart of a communication method provided in an embodiment of the present application. In the method shown in FIG2 , the reference channel and the target channel are channels corresponding to frequency domain units. The subband is described below as an example of a frequency domain unit. The reference channel can be a channel corresponding to a reference subband, or simply referred to as a channel of a reference subband; the target channel can be a channel corresponding to a target subband, or simply referred to as a channel of a target subband. It can be understood that the subband is only an example of a frequency domain unit, and the subband can also be replaced by a frequency domain unit.

[0165] The method 200 shown in Figure 2 includes steps 210 to 250. Each step in the method 200 is described in detail below.

[0166] In step 210, the network device sends a first reference signal, which is transmitted on a reference channel and a target channel. Correspondingly, the terminal receives the first reference signal.

[0167] The first reference signal may be a reference signal sent by a network device for channel measurement, such as a channel state information (CSI)-reference signal (RS) or other signal that can be used to implement the same or similar functions. For more detailed information about the transmission and reception of the first reference signal, please refer to the existing technology and will not be repeated here.

[0168] The first reference signal is transmitted on the reference channel and the target channel. This means that the transmission resources for the first reference signal may include both the reference channel and the target channel. Transmission includes both sending and receiving. The names "reference channel" and "target channel" are simply for ease of distinction and do not limit the transmission of the first reference signal on either channel or the size of the transmission resources for the first reference signal.

[0169] In this embodiment, the resources occupied by the first reference signal in the frequency domain may include multiple subbands, or in other words, the first reference signal is transmitted on multiple subbands, and the multiple subbands include reference subbands and target subbands. In other words, the first reference signal is transmitted on the reference subband and the target subband. The channel of the reference subband is an example of a reference channel, and the channel of the target subband is an example of a target channel. The reference subband is a subband whose channel quality is to be measured and reported, and the target subband is a subband whose channel quality is to be estimated. The reference subband and the target subband are named for the convenience of distinction. The reference subband can be any one or more of the multiple subbands, and the target subband can also be any one or more of the multiple subbands. This application does not limit the number of reference subbands and the number of target subbands.

[0170] In step 220, the terminal determines a channel measurement result and related parameters of a reference channel based on the received first reference signal.

[0171] Exemplarily, a possible implementation method of step 220 is that the terminal estimates the reference channel and the target channel based on the received first reference signal to obtain a channel estimation result of the reference channel and a channel estimation result of the target channel; performs channel measurement on the reference channel to obtain a channel measurement result of the reference channel; determines the weighting coefficient corresponding to the extreme spectral density function of the reference channel and the weighting coefficient corresponding to the extreme spectral density function of the target channel based on the channel estimation result of the reference channel, the channel estimation result of the target channel, and multiple basis functions; determines the relevant parameters according to the weighting coefficient of the extreme spectral density function of the reference channel and the weighting coefficient of the extreme spectral density function of the target channel.

[0172] It will be understood that the channel estimation result of the reference channel may indicate the reference channel, for example, the channel matrix of the reference channel, and the channel estimation result of the target channel may indicate the target channel, for example, the channel matrix of the target channel. Based on the channel matrix and singular value range of the reference channel, the channel matrix and singular value range of the target channel, and multiple basis functions, the weighting coefficients of the limiting spectral density function of the reference channel and the weighting coefficients of the limiting spectral density function of the target channel are determined. That is, based on the channel matrix of the reference channel, the channel matrix of the target channel, and multiple basis functions, the weighting coefficients corresponding to the limiting spectral density function of the reference channel and the weighting coefficients corresponding to the limiting spectral density function of the target channel are determined.

[0173] Since the first reference signal passes through the channel during transmission, the terminal can measure the channel of the reference subband based on the received first reference signal and the predicted first reference signal to obtain a channel measurement result of the reference subband.

[0174] In this embodiment, the channel measurement result of the reference channel, that is, the measurement result of the channel corresponding to the reference subband, can be referred to as the channel measurement result of the reference subband. The channel measurement result of the reference subband includes the CQI corresponding to each transmission layer in one or more transmission layers on the channel corresponding to the reference subband, that is, the aforementioned stream-level CQI. The channel measurement result of the reference subband can be obtained according to existing technologies. For example, the terminal can receive a first reference signal on the reference subband, perform channel estimation based on the received first reference signal, and obtain the rank of the channel. The terminal can traverse each transmission layer based on the rank of the channel, calculate the SINR corresponding to each transmission layer, and then obtain the CQI corresponding to each transmission layer (that is, stream-level CQI). It can be understood that there are as many stream-level CQIs as there are transmission layers into which the channel can be divided in the spatial domain.

[0175] Those skilled in the art will appreciate that if the terminal feeds back the stream-level CQI corresponding to each subband to the network device, it will facilitate more reasonable scheduling of the network device. To avoid huge feedback overhead, the present application estimates the channels corresponding to the target subband and the reference subband, obtains the channel estimation results for the target subband and the reference subband, and then, based on the limiting spectral density function and limiting spectral distribution function of the channels corresponding to the target subband and the reference subband, indicates the relationship between the limiting spectral density function of the channel of the target subband and the limiting spectral density function of the channel of the reference subband through relevant parameters.

[0176] Because the channel's limiting spectral density function and limiting spectral distribution function are parameters that statistically describe the distribution of the channel's singular values, they can be used to indicate the singular values ​​corresponding to each of one or more transmission layers in the channel. For example, if the number of transmission layers is R, the singular values ​​corresponding to the distribution of these R transmission layers can be represented by a vector of length R.

[0177] Figure 3 shows the channel singular value distribution curve. As shown in Figure 3, the abscissa of the curve represents the order, and the ordinate represents the singular value corresponding to the order. The order corresponds to the transmission layer, and the singular value of the rth transmission layer is the singular value corresponding to the order r on the abscissa.

[0178] The limiting spectral density function of the channel of the reference subband may be used to indicate the singular value corresponding to each transmission layer on the channel corresponding to the reference subband. The limiting spectral density function of the channel of the target subband may be used to indicate the singular value corresponding to each transmission layer on the channel corresponding to the target subband.

[0179] For Massive MIMO, the channel matrix can be viewed as a large-dimensional random matrix. Based on the similarity of the limiting spectra of large-dimensional random matrices, the relationship between stream-level CQIs across subbands can be characterized by the relationship between channels. Therefore, the terminal can determine the relationship between the target channel and the reference channel.

[0180] In one possible implementation, the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel can each be represented by a weighted sum of multiple basis functions. These multiple basis functions are common, or in other words, shared, for the target subband and the reference subband and can be referred to as common basis functions for the target channel and the reference channel.

[0181] In this embodiment, the relationship between the target channel and the reference channel can be obtained based on the weighted sum of the multiple common basis functions, which respectively represent the limiting spectral density functions of the channel matrices of the target subband and the reference subband. Then, this relationship and the measured values ​​of the singular values ​​corresponding to each transmission layer on the reference channel can be used to obtain the target estimated values ​​of the singular values ​​corresponding to each transmission layer on the target channel.

[0182] Optionally, the relevant parameters include a weighting coefficient corresponding to the limiting spectral density function of the reference channel and a weighting coefficient corresponding to the limiting spectral density function of the target channel.

[0183] In this embodiment, the relevant parameters may specifically include a weighting coefficient corresponding to the limiting spectral density function of the channel of the reference sub-band and a weighting coefficient corresponding to the limiting spectral density function of the channel of the target sub-band.

[0184] From steps one and two of the previous algorithm, it can be seen that based on the weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the reference subband and the above-mentioned multiple basis functions, the limiting spectral density function of the channel matrix of the reference subband can be weighted to obtain the limiting spectral density function. Based on the same multiple basis functions and the weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the target subband, the limiting spectral density of the channel matrix of the target subband can be weighted to obtain the limiting spectral density.

[0185] The process of determining the weighting coefficients corresponding to the target subband channel matrix and the weighting coefficients corresponding to the limiting spectral density function of the reference subband channel matrix can be found in steps 1 and 2 of the above algorithm and will not be repeated here.

[0186] Exemplarily, the number of common basis functions is K, and the related parameters include K weighting coefficients of the limiting spectral density function of the channel matrix H2 corresponding to the reference subband, and K weighting coefficients of the limiting spectral density function of the channel matrix H1 corresponding to the target subband. If the K weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the reference subband and the K weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the target subband are respectively represented by vectors, then the K weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the reference subband can be expressed as: The K weighting coefficients corresponding to the limiting spectral density function of the channel matrix of the reference subband can be expressed as:

[0187] For the convenience of explanation below, the weighting coefficient corresponding to the extreme spectral density function of the channel matrix is ​​referred to as the weighting coefficient corresponding to the channel matrix.

[0188] Optionally, the relevant parameters include a ratio corresponding to each of the one or more transmission layers. Taking the first transmission layer of the one or more transmission layers as an example, the ratio corresponding to the first transmission layer is: a ratio of an initial estimate of a singular value corresponding to the first transmission layer on a target channel to an initial estimate of a singular value corresponding to the first transmission layer on a reference channel, or a ratio of an initial estimate of a singular value corresponding to the first transmission layer on a reference channel to an initial estimate of a singular value corresponding to the first transmission layer on a target channel.

[0189] In this embodiment, the ratio corresponding to the first transmission layer is: the ratio of the initial singular value of the singular value corresponding to the first transmission layer on the channel of the target subband to the initial estimated value of the singular value corresponding to the first transmission layer on the channel of the reference subband, or the ratio of the initial estimated value of the singular value corresponding to the first transmission layer on the channel of the reference subband to the initial estimated value of the singular value corresponding to the first transmission layer on the channel of the target subband.

[0190] It should be understood that the first transmission layer can be any one of the one or more transmission layers mentioned above. Assuming that the channel is divided into R transmission layers, the relevant parameters include R ratios corresponding to the R transmission layers. The ratio of the rth transmission layer (r can be an integer value from 0 to R-1) is: the ratio of the initial estimated value of the singular value corresponding to the rth transmission layer on the channel of the target subband to the initial estimated value of the singular value corresponding to the rth transmission layer on the channel of the reference subband, or the ratio of the initial estimated value of the singular value corresponding to the rth transmission layer on the channel of the reference subband to the initial estimated value of the singular value corresponding to the rth transmission layer on the target subband.

[0191] The process of determining the ratio corresponding to each of the one or more transmission layers may refer to steps 1 and 2 in the above algorithm and will not be described in detail.

[0192] Exemplarily, the channel is divided into R transmission layers, and the relevant parameters include a ratio corresponding to each of the R transmission layers. If the ratio corresponding to the distribution of the R transmission layers is represented by a vector, it can be expressed as: or

[0193] It should be understood that the two possible forms of the relevant parameters listed above are merely examples. Based on the same concept, those skilled in the art can also perform simple mathematical transformations on this basis to obtain other possible forms of the relevant parameters. These other forms of the relevant parameters obtained through simple mathematical transformations are intended to fall within the scope of protection of this application.

[0194] In step 230, the terminal sends first indication information, where the first indication information is used to indicate the channel measurement result of the reference channel and related parameters of the reference channel and the target channel. Correspondingly, the network device receives the first indication information.

[0195] The terminal may send the channel measurement result of the reference channel measured in step 220 (ie, the channel measurement result of the reference subband) and related parameters indicating the relationship between the target channel and the reference channel to the network device via first indication information.

[0196] As previously described, in this embodiment, the channel measurement result includes the CQI corresponding to each of the R transmission layers on the channel of the reference subband, i.e., R stream-level CQIs. This correlation parameter can be used to indicate the relationship between the channel of the reference subband and the channel of the target subband, so that the network device can estimate the stream-level CQI of the target subband based on the stream-level CQI of the reference subband.

[0197] Exemplarily, the first indication information may be carried in CSI. The CSI may, for example, be carried in uplink control information (UCI) sent by the terminal to the network device. The UCI may, for example, be transmitted via a physical uplink control channel (PUCCH). The specific process of the terminal sending CSI to the network device can be found in existing technologies and will not be described in detail here.

[0198] In step 240, the network device determines a CQI corresponding to each of the one or more transmission layers on the target channel according to the channel measurement result and related parameters of the reference channel.

[0199] For example, in a RAN deployed with a CU, DU, and RU, step 240 may be specifically implemented as follows: the DU determines the CQI corresponding to each of one or more transmission layers on the channel of the target subband based on the channel measurement results and related parameters of the reference channel. In an ORAN, step 240 may be specifically implemented as follows: the O-DU determines the CQI corresponding to each of one or more transmission layers on the target channel based on the channel measurement results and related parameters of the reference channel.

[0200] In this embodiment, the network device may determine the stream-level CQI of the target sub-band according to the channel measurement result and related parameters of the reference sub-band indicated by the first indication information.

[0201] As shown in step 210, the channel measurement results for the reference subband include the CQI corresponding to each transmission layer in one or more transmission layers on the channel of the reference subband. Related parameters may include weighting coefficients corresponding to the channel matrix of the reference subband and the weighting coefficients corresponding to the channel matrix of the target subband; they may also include ratios corresponding to each transmission layer in the one or more transmission layers. The network device may perform different operations based on the different related parameters to determine the singular values ​​corresponding to each transmission layer on the channel of the target subband, and thereby determine the CQI corresponding to each transmission layer on the channel of the target subband.

[0202] The CQI for each transmission layer on the channel corresponding to the reference subband can be determined by the SNR of that transmission layer, that is, the ratio of the signal power to the noise power. The singular values ​​of each transmission layer can be used to determine the power of the signal transmitted on each transmission layer. By measuring the floor, the power of the noise on the floor can be obtained, from which the SNR of each transmission layer can be obtained, and thus the CQI corresponding to each transmission layer can be obtained.

[0203] The following describes, using the two possible forms of the relevant parameters provided above, the process by which a network device determines the singular values ​​for each transmission layer on the target subband's channel based on the reference subband's channel measurement results and the relevant parameters. It should be understood that the singular values ​​for each transmission layer on the target subband's channel determined by the network device based on the reference subband's channel measurement results and the relevant parameters are target estimates of the singular values ​​for each transmission layer on the target subband, or in other words, the estimated singular values ​​for each transmission layer on the target subband's channel.

[0204] In one possible case, the relevant parameters include a weighting coefficient corresponding to the limiting spectral density function of the channel of the reference sub-band and a weighting coefficient corresponding to the limiting spectral density function of the channel of the target sub-band.

[0205] As explained in step 2 of the algorithm above, multiple common basis functions and the weighting coefficients corresponding to the reference subband and target subband channel matrices, respectively, can be used to perform inverse variable substitution to obtain the limiting spectral density function and limiting spectral distribution function of the reference subband and target subband channel matrices within their respective singular value ranges. The order statistics of the reference subband and target subband channel matrices can then be determined from these limiting spectral density functions and limiting spectral distribution functions, respectively, to obtain initial estimates of the singular values ​​of the reference subband and target subband channel matrices corresponding to each transmission layer. This allows the ratio corresponding to each transmission layer to be obtained.

[0206] Taking R transmission layers as an example, the network device can determine the ratio for each transmission layer in the R transmission layers based on the weighting coefficient corresponding to the channel matrix of the reference subband and the weighting coefficient corresponding to the channel matrix of the target subband. The ratio corresponding to the rth transmission layer in the R transmission layers is: the ratio of the initial estimated value of the singular value of the rth transmission layer on the channel of the target subband to the initial estimated value of the singular value of the rth transmission layer on the channel of the reference subband, or the ratio of the initial estimated value of the singular value of the rth transmission layer on the channel of the reference subband to the initial estimated value of the singular value of the rth transmission layer on the target subband.

[0207] Referring to step 3 of the above algorithm, based on the ratio of each transmission layer and the measured value of the singular value of the rth transmission layer of the reference subband, the target estimated value of the singular value of the rth transmission layer of the target subband can be determined.

[0208] Another possible scenario is that the relevant parameter comprises a ratio corresponding to each of the one or more transmission layers.

[0209] As explained in step 3 of the above algorithm, based on the ratio of each transmission layer and the measured value of the singular value of the r-th transmission layer of the reference subband, the target estimated value of the singular value of the r-th transmission layer of the target subband can be determined.

[0210] Regarding the process of determining the singular value of each transmission layer on the channel of the reference subband based on the channel measurement results and related parameters of the reference subband, please refer to steps 2 and 3 in the above algorithm and will not be repeated here.

[0211] Based on the above scheme, the terminal can obtain the relevant parameters between the reference subband and the target subband by statistically analyzing the extreme spectral density function and the extreme spectral distribution function of the channel matrix corresponding to the target subband and the reference subband, and feedback the CQI and related parameters of each transmission layer on the reference subband to the network device. In this way, the network device can determine the CQI of each transmission layer on the channel of the target subband based on the CQI and related parameters of each transmission layer on the channel of the reference subband. Therefore, the terminal only needs to feedback the CQI of the transmission layer of a small number of reference subbands and related parameters indicating the relationship between subbands, and the network device can obtain the CQI of the transmission layer of more subbands. As a result, it can provide richer channel state information for the scheduling of network devices, so that the network devices can schedule more reasonably and improve spectrum efficiency. In other words, it can exchange a small amount of feedback overhead for the improvement of spectrum efficiency.

[0212] In order to better understand the method provided by this application and the effects it brings, it is described below with reference to FIG4 .

[0213] Figure 4 illustrates the process of method 200 from the perspective of the channel singular value distribution curve. In Figure 4, subband 1 is an example of a reference subband, and subband 2 is an example of a target subband. The left side of Figure 4 shows the channel singular value distribution curve for subband 1. The solid line in the figure shows the actual channel singular value distribution curve, which can be understood as the measured channel singular value distribution curve; the dashed line shows the curve representing the channel singular value distribution via the weighted sum of multiple basis functions, i.e., the curve obtained by the weighted sum of multiple basis functions. Step 1 is the process of obtaining the limiting spectral distribution density function for subband 1. Specifically, the actual channel singular value distribution curve is represented by the weighted sum of multiple basis functions, thereby obtaining the corresponding weighting coefficients for the channel of subband 1. As can be seen, the solid line and the dashed line are quite close. In other words, the weighted sum of multiple basis functions can accurately represent the channel singular value distribution of subband 1.

[0214] Steps 2 and 3 utilize the similarity of the limiting spectral densities to determine the channel singular value distribution for subband 2. First, determine whether the channel singular value distribution for subband 2 can be determined using the similarity of the limiting spectral densities. The limiting spectral density functions of the channels of subband 1 and subband 2 are characterized by a weighted sum of the aforementioned multiple basis functions. The distance between the weighting coefficients corresponding to the channels of subband 1 and subband 2 is then calculated. If the distance between the two is determined to be less than or equal to a preset threshold, the weighted sum of the multiple basis functions can be used to estimate the actual channel singular value distribution curve for subband 2.

[0215] For more detailed description of each step in FIG. 4 , please refer to steps 220 to 240 above, and the related description of step 250 below, which will not be repeated here.

[0216] For easier understanding, an example is used below to illustrate the CQI feedback overhead caused by the solution provided in this embodiment.

[0217] Assuming that the bandwidth allocated by the network device to the terminal includes 273 RBs and each subband includes 16 RBs, the bandwidth includes ceil(273 / 16)=18 subbands in total. The channel can support data transmission of a single user (SU) with a maximum of 32 transmission layers, that is, 32 streams.

[0218] If each subband feeds back a stream-level CQI, each stream-level CQI requires 4 bits of overhead, and the total feedback overhead required is: 4×32×18=2304 (bits).

[0219] If the 18 subbands are divided into 6 groups, each group of subbands includes 1 reference subband and 5 target subbands. Feedback of stream-level CQI for the reference subband requires 4 bits of overhead for each stream-level CQI. Feedback of related parameters (such as weighting coefficients) for the target subband requires 5 bits of overhead for each weighting coefficient. There are 4 basis functions, and each subband can feedback 4 weighting coefficients. The total feedback overhead required is: 4×32×(18 / 6)+4×5×18=744 (bits).

[0220] It can be seen that if the existing technology is used to perform stream-level CQI feedback, the feedback overhead it brings will be much higher than the feedback overhead brought by adopting this solution.

[0221] The above scheme utilizes the similarity of the extreme spectrum of large-dimensional random matrices. Through the relationship between the channels of multiple relatively similar sub-bands (such as the reference sub-band and the target sub-band), the CQI of the transmission level on the channel of some sub-bands is used to characterize the CQI of the transmission level on the channel of another sub-band.

[0222] Those skilled in the art will appreciate that channels vary depending on their frequency domain locations, and therefore the weighting coefficients corresponding to the channel matrices at different frequency domain locations may also vary. Figure 5 illustrates the differences between the weighting coefficients corresponding to the channel matrices for different subbands.

[0223] The curves shown in Figure 5 are obtained using the following parameters and assumptions: a clustered delay line (CDL)-A model of 100 nanoseconds (ns), 10 RBs, one RB per subband, and RB 1 as the reference subband. It can be seen that as the RB index increases (i.e., the distance from the reference subband RB 1), the distance between the weighting coefficients corresponding to the subband's channel matrix and the weighting coefficients corresponding to the reference subband's channel matrix also increases. The distance between the weighting coefficients corresponding to the channel matrices of RBs 2 through RB 5 and the weighting coefficients corresponding to the reference subband RB 1 is relatively small, less than or equal to 0.1. The distance between the weighting coefficients corresponding to the channel matrices of RBs 6 through RB 10 and the weighting coefficients corresponding to the reference subband RB 1 is relatively large, greater than 0.1.

[0224] It can be understood that the distance between the weighting coefficients corresponding to the channel matrices of two subbands can be used to represent the similarity between the weighting coefficients corresponding to the channel matrices of the two subbands. The longer the distance, the lower the similarity; the closer the distance, the higher the similarity.

[0225] Therefore, before executing the above steps 220 to 240, one of the network devices or terminals can first determine whether the weighting coefficients corresponding to the channel matrix of the target subband and the weighting coefficients corresponding to the channel matrix of the reference subband are similar. If they are similar, steps 220 to 240 are executed. If they are not similar, other methods can be used, such as feeding back the CQIs corresponding to each transmission layer on the channel of the target subband, or finding other subbands with weighting coefficients similar to those corresponding to the channel matrix of the target subband as reference subbands, and then executing steps 220 to 240.

[0226] FIG. 6 is a schematic diagram showing a process performed before step 220 of method 200 .

[0227] As shown in Figure 4, the terminal can first obtain the channel matrix of the target subband, and then calculate the limiting spectral density function and limiting spectral distribution function of the channel matrix H1 of the target subband; on the other hand, the terminal can obtain the limiting spectral density and limiting spectral distribution of the channel matrix H2 of the reference subband. The terminal can represent the limiting spectral density functions of the channel matrices H1 and H2 respectively based on multiple (for example, K) common basis functions by the weighted sum of the multiple common basis functions, thereby obtaining the weighting coefficients corresponding to the channel matrix H1 (for example, ) and the weighting coefficients corresponding to the channel matrix H2 (such as The terminal may calculate a distance, such as a Euclidean distance, between the weight coefficients corresponding to the channel matrix H1 and the weight coefficients corresponding to the channel matrix H2 to determine whether the two are similar.

[0228] Take the Euclidean distance as an example. To calculate the Euclidean distance between the two, we can first calculate the weighted coefficient corresponding to the channel matrix H1. The weighting coefficients corresponding to the channel matrix H2 Normalization is performed to obtain a vector x representing the weighting coefficients corresponding to the channel matrix H1 and a vector y representing the weighting coefficients corresponding to the channel matrix H2. The vectors x and y satisfy the following conditions: ||x||2=1, ||y||2=1. Here, ||||2 represents the binary norm of the vector, or the Euclidean norm. The Euclidean distance of the weighting coefficients corresponding to the channel matrix H1 relative to the weighting coefficients corresponding to the channel matrix H2 can be expressed as: ||xy||2. Assume that the preset threshold is ε, illustratively, ε is 0.1. If the distance between the weighting coefficients corresponding to the channel matrix H1 and the weighting coefficients corresponding to the channel matrix H2 of the reference subband satisfies ||xy||2≤ε, then steps 210 to 230 above can be performed. If the distance between the weighting coefficient corresponding to the channel matrix H1 and the weighting coefficient corresponding to the channel matrix H2 of the reference subband does not satisfy ||xy||2≤ε, or in other words, ||xy||2>ε, other methods can be used, such as feeding back the CQI corresponding to each transmission layer on the channel of the target subband, or finding other subbands with a closer (or similar) distance to the weighting coefficient corresponding to the channel matrix of the target subband as reference subbands, and then executing steps 220 to 240, which will not be repeated here.

[0229] For example, if the distance between the weighting coefficients corresponding to the channel matrices of each subband in RB 2 to RB 5 in Figure 5 and the weighting coefficients corresponding to the channel matrix of subband RB1 is less than or equal to 0.1, then subband RB1 can be used as the reference subband; while if the distance between the weighting coefficients corresponding to the channel matrices of each subband in RB6 to RB10 and the weighting coefficients corresponding to the channel matrix of subband RB1 is greater than 0.1, then subband RB1 is not used as the reference subband, and other methods can be used.

[0230] It should be understood that the Euclidean distance is only one possible implementation method for calculating the distance between the weighted coefficients corresponding to the channel matrices of two subbands, and should not constitute any limitation to this application. The distance may also be, for example, the Watsonstein distance (also known as the earth mover's distance), the Jensen-Shannon divergence (JS divergence, referred to as JS divergence), the normalized cross-correlation coefficient, etc. The formula for calculating the distance in the above example may also be adjusted accordingly, and this application does not limit this. For other examples of the above distances and their possible implementation methods, please refer to the existing technology and will not be described in detail herein.

[0231] In another possible implementation, the terminal may pre-group the subbands included in the allocated bandwidth, and group multiple subbands with high similarity as a group. Subbands in the same group may be fed back based on the same reference subband, while subbands with low similarity may be divided into different groups and fed back based on different reference subbands.

[0232] Optionally, the reference subband and the target subband belong to a group of subbands, the group of subbands includes multiple subbands, the multiple basis functions are common basis functions of the multiple subbands, and the distance between the weighting coefficient corresponding to the channel matrix of any one of the multiple subbands and the weighting coefficient corresponding to the channel matrix of the reference subband is less than or equal to a preset threshold.

[0233] For the convenience of distinction and explanation, in this article, the bandwidth occupied by multiple sub-bands in the frequency domain whose distance of weighted coefficients corresponding to the channel matrix is ​​less than or equal to the preset threshold is recorded as the first frequency band. The first frequency band includes multiple sub-bands, and the multiple sub-bands may include a reference sub-band and at least one target sub-band.

[0234] Optionally, before step 220, the method further includes step 250: the network device sends first configuration information to the terminal, where the first configuration information is used to configure one or more of the following: one or more first frequency bands, a reference subband within each first frequency band, or multiple basis functions corresponding to each first frequency band. Accordingly, the terminal receives the first configuration information from the network device.

[0235] That is to say, the network device can pre-group multiple sub-bands within the bandwidth allocated to the terminal and configure the grouping results to the terminal. As mentioned above, the bandwidth allocated to the terminal may have one or more first frequency bands. Therefore, the network device can configure one or more first frequency bands through the first configuration information. Exemplarily, when the first configuration information is used to configure one or more first frequency bands, it can indicate one or more of the following for each first frequency band: size, starting position or ending position. Among them, the size can be expressed by bandwidth, or by the number of frequency domain units (such as subbands) included; the starting position and ending position can be represented by the index of the frequency domain unit (such as a subband or subcarrier). When there are multiple first frequency bands and the sizes of the multiple first frequency bands are the same, the sizes, starting positions and ending positions of the multiple first frequency bands can be indirectly indicated by one or more of the size, starting position or ending position of one of the first frequency bands (such as the first one in the frequency domain).

[0236] The size and position of the first frequency band may vary, or in other words, the subbands included in each first frequency band (or in other words, each group of subbands) may vary. For example, the network device may determine the size of the first frequency band and its subbands based on the stream-level CQI and / or other channel measurement results previously fed back by the terminal, and configure one or more first frequency bands for the terminal through the first configuration information.

[0237] The size and position of the first frequency band may also be fixed. In other words, the subbands included in each first frequency band (or each group of subbands) may also be fixed, such as pre-defined by a protocol, or may not change after being configured by the network device through signaling. Therefore, the network device does not necessarily configure the first frequency band each time it sends the first configuration information, nor does the network device necessarily send the first configuration information before each time it sends the first reference signal.

[0238] The terminal can determine the reference subband and the target subband based on the size and position of each first frequency band. For example, the terminal can determine the reference subband and the target subband of each first frequency band according to a preset rule, and the preset rule is, for example: the first subband in the same first frequency band is the reference subband, or the subband in the middle position in the same first frequency band is the reference subband, and so on. Thus, other subbands in the first frequency band except the reference subband can be determined as target subbands. For another example, the device can configure the reference subband through the first configuration information, such as indicating the index of the reference subband, and so on, without limitation.

[0239] When there are multiple first frequency bands, the multiple basis functions corresponding to different first frequency bands can be the same. In other words, the multiple basis functions can be common to different first frequency bands, or shared within the bandwidth allocated to the terminal. The multiple basis functions corresponding to different first frequency bands can also be different. In other words, the multiple basis functions can be independent of each other among different first frequency bands. The multiple basis functions corresponding to each first frequency band can be configured by the network device through the first configuration information, or can be predefined by the protocol, which is not limited in this application.

[0240] It should be noted that when a network device configures one or more first frequency bands, a reference subband within each first frequency band, or any one of the multiple basis functions corresponding to each first frequency band through first configuration information, it does not mean that the network device indicates any one of the above multiple items in each first configuration information sent. As long as the terminal can determine one or more of the above multiple items based on the first configuration information from the network device, it can be considered that the first configuration information is used to configure one or more of the above multiple items. In other words, this application does not limit how the network device configures one or more first frequency bands, the reference subband within each first frequency band, and the multiple basis functions corresponding to each first frequency band.

[0241] FIG7 exemplarily shows a process of the network device grouping multiple sub-bands (ie, determining the first frequency band). The process shown in FIG7 can be implemented before step 250 of the method 200.

[0242] As shown in FIG. 7 , the process includes steps 710 to 760 .

[0243] In step 710, the network device sends a second reference signal, which is transmitted on multiple sub-bands. Correspondingly, the terminal receives the second reference signal.

[0244] The second reference signal may be a reference signal sent by the network device before the first reference signal mentioned in step 210, for example, a CSI-RS or other signal that can be used to implement the same or similar functions.

[0245] For more detailed processes of sending and receiving the second reference signal, please refer to the existing technology and will not be described in detail here.

[0246] In step 720, the terminal determines a weighting coefficient corresponding to a limiting spectral density function of a channel of each of a plurality of sub-bands within a preset bandwidth based on the received second reference signal.

[0247] The terminal can estimate the channel matrix of each subband in the multiple subbands in which the second reference signal is transmitted based on the received second reference signal, and then calculate the limiting spectral density function of the channel matrix of each subband, and determine the weighting coefficient corresponding to the channel matrix of each subband based on multiple common basis functions.

[0248] The multiple subbands may be all subbands within the bandwidth (e.g., a bandwidth part (BWP)) allocated to the terminal, or a portion thereof. In other words, the multiple subbands may be subsets of the BWP. The network device may pre-indicate the multiple subbands through configuration information, i.e., indicate the subbands for which channel estimation is required. Optionally, before step 710, the method further includes step 730: the network device sends third configuration information to the terminal, where the third configuration information is used to configure the multiple subbands. Accordingly, the terminal receives the third configuration information from the network device.

[0249] The terminal may receive the second reference signal on multiple subbands configured by the third configuration information, or may receive the second reference signal on all subbands within the allocated bandwidth, which is not limited in this application.

[0250] The weighting coefficients corresponding to the channel matrices of the multiple subbands may be determined based on multiple common basis functions.

[0251] In one possible implementation, the multiple basis functions are pre-configured to the terminal by the network device via configuration information. Optionally, before step 710, the method further includes step 740: the network device sends fourth configuration information to the terminal, where the fourth configuration information is used to configure the multiple basis functions. Accordingly, the terminal receives the fourth configuration information from the network device.

[0252] In another possible implementation, the multiple basis functions are pre-stored by the terminal. For example, the terminal may locally store multiple basis functions pre-defined by the protocol, or locally store multiple basis functions configured by the network device during the last channel estimation or channel measurement, or independently determine multiple basis functions based on the last channel estimation or channel measurement. This application is not limited to this.

[0253] Exemplarily, the terminal can perform channel estimation for multiple subbands within the bandwidth range along the frequency domain direction, such as along the direction in which the subband index increases successively, and then calculate the weighting coefficients corresponding to the channel matrix of each subband based on the estimated channel matrix and multiple basis functions.

[0254] The specific process of the terminal determining the weighting coefficient corresponding to the channel matrix of each subband based on the received second reference signal can be found in step 1 of the above algorithm and will not be repeated here.

[0255] It should be understood that the third configuration information and the fourth configuration information described above may be information carried in the same signaling. In this case, for the network device, the step of sending the third configuration information in step 730 and the step of sending the fourth configuration information in step 740 may be combined into the same sending step. For the terminal, the step of receiving the third configuration information in step 730 and the step of receiving the fourth configuration information in step 740 may be combined into the same receiving step. The third configuration information and the fourth configuration information may also be information carried in different signaling, which is not limited in this application.

[0256] It should also be understood that the multiple basis functions on which the terminal determines the weighting coefficients corresponding to the extreme spectral density function of the channel matrix of each subband in step 720 are based can be the same as or different from the multiple basis functions used in the above method 200, and this application does not limit this.

[0257] In step 750, the terminal sends second indication information to the network device, where the second indication information is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each sub-band in the multiple sub-bands. Accordingly, the network device receives the second indication information from the terminal.

[0258] The terminal can feed back the calculated weighting coefficients corresponding to the extreme spectral density functions of the channel matrices of the sub-bands to the network device via the second indication information, thereby facilitating the network device to determine which sub-bands can be grouped together and which sub-bands are not suitable for grouping together.

[0259] For a more detailed process of the terminal sending the second indication information to the network device, please refer to the relevant description in step 230 of the method 200, which will not be repeated here.

[0260] In step 760, the network device determines one or more first frequency bands based on the second indication information.

[0261] For example, in a RAN deployed with a CU, DU, and RU, step 760 may be specifically implemented as follows: the DU determines one or more first frequency bands based on the second indication information. In an ORAN, step 760 may be specifically implemented as follows: the O-DU determines one or more first frequency bands based on the second channel indication information of the reference subband.

[0262] The network device may group the multiple subbands along a frequency domain direction, such as along a direction of increasing subband index, based on the weighting coefficient corresponding to the channel matrix of each subband indicated by the second indication information. First, the network device may determine a reference subband 1 as the subband with the smallest index value among the multiple subbands, and sequentially calculate the distance (e.g., Euclidean distance) between the weighting coefficients corresponding to the channel matrices of subbands with other index values ​​and the weighting coefficients corresponding to the channel matrix of reference subband 1. If the distance is less than or equal to a first preset threshold, the subband and reference subband 1 are grouped together. If the distance between the weighting coefficients corresponding to the channel matrix of a subband and the weighting coefficients corresponding to the channel matrix of reference subband 1 is greater than the first preset threshold, the subband may be redefined as a reference subband, such as reference subband 2. The network device then continues to sequentially calculate the distance between the weighting coefficients corresponding to the channel matrices of subbands with other index values ​​and the weighting coefficients corresponding to the channel matrix of reference subband 2 along the bandwidth direction. If the distance is less than or equal to the first preset threshold, the subband and reference subband 2 are grouped together. If the distance between the weighting coefficients corresponding to the channel matrix of a subband and the weighting coefficients corresponding to the channel matrix of reference subband 1 is greater than a first preset threshold, the subband can be redefined as a reference subband, for example, as reference subband 3. Similarly, multiple groups of subbands can be obtained. The multiple groups of subbands obtained in this way are determined by traversing each subband across the entire bandwidth. The sizes of the multiple first frequency bands obtained may be the same or different. In other words, the reference subbands may be evenly or unevenly distributed across the entire bandwidth.

[0263] Alternatively, the network device may calculate the distance between the weighting coefficients corresponding to the channel matrices of some of the multiple subbands and the weighting coefficients corresponding to the channel matrix of reference subband 1, thereby determining one or more subbands that can be grouped together with reference subband 1, i.e., determining a first frequency band, and grouping the multiple subbands using the bandwidth of the first frequency band as the granularity. The multiple reference subbands thus obtained are evenly distributed across the entire bandwidth. Since the allocated bandwidth is not necessarily an integer multiple of the bandwidth of the first frequency band, the bandwidths of the other first frequency bands are the same, except for the first frequency bands near the bandwidth edge, which may differ from the bandwidths of the other first frequency bands.

[0264] Figure 8 is a schematic diagram of a first frequency band provided by an embodiment of the present application. As shown in the figure, the first frequency band includes various subbands, each of which has a frequency domain interval of B1, such as B1 subcarriers or RBs, and a frequency domain interval of B2, such as B2 subcarriers or RBs, where B2 is greater than B1. That is, each first frequency band can include multiple subbands. It is understood that the multiple subbands configured by the network device can be divided into one or more groups of subbands, or in other words, one or more first frequency bands may exist within the bandwidth occupied by the multiple subbands.

[0265] It should be understood that the above-described example of grouping multiple subbands within a bandwidth along the direction of increasing frequency domain subband indices and using the subband with the smallest index value as reference subband 1 is merely one possible example and does not constitute any limitation on this application. This application does not limit the direction in which a network device groups multiple subbands within a bandwidth, nor does it limit how the network device determines reference subbands or the number of reference subbands.

[0266] It should also be understood that the process shown in FIG7 can be performed before the process shown in FIG2 , so that the network device can configure the first frequency band, the reference subband within the first frequency band, and the multiple basis functions for the terminal based on the above grouping. In other words, the process shown in FIG7 can be performed before step 250.

[0267] Based on the above scheme, the network device can group multiple subbands based on the weighting coefficients corresponding to the limiting spectral density functions of the channel matrices of each subband, so that subbands with high similarity in the limiting spectral density functions of the channel matrices are grouped together. Therefore, the limiting spectrum of the channel matrix of the reference subband, on which the terminal's feedback for each target subband is based in subsequent channel measurement and feedback, can be a limiting spectrum with high similarity. When the weighting coefficients corresponding to the limiting spectral density functions of the channels of two subbands have a certain degree of similarity, the CQI of each transmission layer of the target subband estimated based on this similarity and the channel measurement results of the reference subband is accurate. Therefore, by grouping multiple subbands, it is beneficial to obtain more accurate stream-level CQI for each subband, which in turn facilitates more reasonable scheduling of network devices and improves spectrum efficiency.

[0268] Figure 9 is a schematic flow chart of a communication method provided by another embodiment of the present application. Unlike the method shown in Figure 2, in the method shown in Figure 9, the reference channel and the target channel correspond to time units. The reference channel can be a channel corresponding to a reference time unit, and the target channel can be a channel corresponding to a target time unit.

[0269] The method 900 shown in Figure 9 includes steps 910 to 950. Each step in the method 900 is described in detail below.

[0270] In step 910, a network device sends a first reference signal, which is transmitted on a reference channel and a target channel. Correspondingly, a terminal receives the first reference signal.

[0271] The first reference signal may be a reference signal sent by a network device for channel measurement, such as a CSI-RS or other signal that can be used to implement the same or similar functions. For more detailed information about the transmission and reception of the first reference signal, please refer to the existing technology and will not be repeated here.

[0272] The first reference signal is transmitted on the reference channel and the target channel. In this embodiment, the resources occupied by the first reference signal in the time domain may include multiple time units, or in other words, the first reference signal is transmitted on multiple time units. The multiple time units include a reference time unit and a target time unit. In other words, the first reference signal is transmitted on the reference time unit and the target time unit. Among them, the channel corresponding to the reference time unit is an example of a reference channel, and the channel corresponding to the target time unit is an example of a target channel. The reference time unit is the time unit corresponding to the channel whose channel quality is to be measured and reported, and the target time unit is the time unit corresponding to the channel whose channel quality is to be estimated. The reference time unit and the target time unit are named for the convenience of distinction. The reference time unit may be any one or more of the multiple time units, and the target time unit may also be any one or more of the multiple time units. This application does not limit the number of reference time units and the number of target time units.

[0273] In step 920, the terminal determines a channel measurement result of the reference channel and related parameters of the reference channel and the target channel based on the received first reference signal.

[0274] Since the first reference signal passes through the channel during transmission, the terminal can measure the channel corresponding to the reference time unit based on the received first reference signal and the predicted first reference signal to obtain the channel measurement result corresponding to the reference time unit.

[0275] In this embodiment, the channel measurement result of the reference channel, i.e., the measurement result of the channel corresponding to the reference time unit, may be referred to as the channel measurement result of the reference time unit. The channel measurement result of the reference time unit includes the CQI corresponding to each transmission layer in one or more transmission layers on the channel corresponding to the reference time unit, i.e., the aforementioned stream-level CQI.

[0276] The channel measurement result of the reference time unit can be obtained according to existing technologies. For details, please refer to the relevant description in step 220 of method 200, which will not be repeated here.

[0277] Those skilled in the art will understand that if the terminal feeds back the stream-level CQI corresponding to each time unit to the network device, the network device can obtain richer channel state information, which is conducive to more reasonable scheduling of the network device. In order to avoid huge feedback overhead, the present application estimates the channels corresponding to the target time unit and the reference time unit respectively, obtains the channel estimation result of the target time unit and the channel estimation result of the reference time unit (it can be understood that the channel estimation result of the target time unit indicates the estimated channel corresponding to the target time unit, and the channel estimation result of the reference time unit indicates the estimated channel corresponding to the reference time unit), and then based on the extreme spectral density function and the extreme spectral distribution function of the channel corresponding to the target time unit and the reference time unit respectively, the relationship between the extreme spectral density function of the channel corresponding to the target time unit and the extreme spectral density function of the channel corresponding to the reference time unit is indicated by relevant parameters. In this way, the terminal can feedback the stream-level CQI corresponding to each reference time unit once every period of time, and feedback the relevant parameters used to indicate the relationship between the reference channel and the target channel at other times.

[0278] In one possible implementation, the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel can each be represented by a weighted sum of multiple basis functions. These multiple basis functions are common to the target channel and the reference channel, and can be referred to as common basis functions of the target channel and the reference channel.

[0279] In this embodiment, the weighted sum of the multiple common basis functions respectively represents the limiting spectral density function of the channel matrix corresponding to the reference time unit and the limiting spectral density function of the channel matrix corresponding to the target time unit, so as to obtain the relationship between the target time unit and the reference time unit, and then utilize this relationship and the measured values ​​of the singular values ​​corresponding to each transmission layer on the reference channel to obtain the target estimated values ​​of the singular values ​​corresponding to each transmission layer on the target channel.

[0280] Optionally, the relevant parameters include a weighting coefficient corresponding to the limiting spectral density function of the reference channel and a weighting coefficient corresponding to the limiting spectral density function of the target channel.

[0281] In this embodiment, the relevant parameters may specifically include a weighting coefficient corresponding to the limiting spectral density function of the channel corresponding to the reference time unit and a weighting coefficient corresponding to the limiting spectral density function of the channel matrix corresponding to the target time unit.

[0282] Optionally, the relevant parameters include a ratio corresponding to each of the one or more transmission layers. Taking the first transmission layer of the one or more transmission layers as an example, the ratio corresponding to the first transmission layer is: a ratio of an initial estimate of singular values ​​corresponding to the first transmission layer on the target channel to an initial estimate of singular values ​​corresponding to the first transmission layer on the reference channel, or a ratio of an initial estimate of singular values ​​corresponding to the first transmission layer on the reference channel to an initial estimate of singular values ​​corresponding to the first transmission layer on the target channel.

[0283] In this embodiment, the ratio corresponding to the first transmission layer is: the ratio of the initial singular value of the singular value corresponding to the first transmission layer on the channel corresponding to the target time unit to the initial estimated value of the singular value corresponding to the first transmission layer on the channel corresponding to the reference time unit, or the ratio of the initial estimated value of the singular value corresponding to the first transmission layer on the channel corresponding to the reference time unit to the initial estimated value of the singular value corresponding to the first transmission layer on the channel corresponding to the target time unit.

[0284] For more detailed description of the relevant parameters, please refer to the relevant description in step 220 of method 200, which will not be repeated here.

[0285] In step 930, the terminal sends first indication information, where the first indication information is used to indicate the channel measurement result and related parameters of the reference channel. Correspondingly, the network device receives the first indication information.

[0286] The terminal may send the channel measurement result of the reference channel measured in step 920 (ie, the channel measurement result of the reference time unit) and relevant parameters for indicating the relationship between the target channel and the reference channel to the network device via the first indication information.

[0287] The channel measurement result of the reference channel includes the CQI corresponding to each of the R transmission layers on the channel corresponding to the reference time unit, that is, R stream-level CQIs. The related parameters can be used to indicate the relationship between the channel of the target time unit and the channel of the reference time unit.

[0288] For more detailed description of the terminal sending the first indication information to the network device, please refer to the relevant description in step 230 of the above method 200, which will not be repeated here.

[0289] In step 940, the network device determines a CQI corresponding to each of the one or more transmission layers on the target channel according to the channel measurement result and related parameters of the reference channel.

[0290] In this embodiment, the network device may determine the stream-level CQI of the channel corresponding to the target time unit according to the channel measurement result and related parameters of the reference time unit indicated by the first indication information.

[0291] As described in step 910, the channel measurement result for the reference time unit includes the CQI corresponding to each transmission layer in one or more transmission layers on the channel corresponding to the reference time unit. Related parameters may include weighting coefficients corresponding to the limiting spectral density function of the target channel and the reference channel, and may also include ratios corresponding to each transmission layer in the one or more transmission layers. The network device may perform different operations based on the different related parameters to determine the singular value corresponding to each transmission layer on the channel corresponding to the target time unit, and thereby determine the CQI corresponding to each transmission layer on the channel corresponding to the target time unit.

[0292] The determination of the CQI corresponding to each transmission layer on the channel corresponding to the reference time unit and the CQI corresponding to each transmission layer on the channel corresponding to the target time unit can be referred to the relevant description in step 240 of the method 200 and will not be repeated here.

[0293] The above scheme utilizes the similarity of the extreme spectrum of large-dimensional random matrices. Through the relationship between the channel matrices of multiple relatively similar time units (such as reference time units and target time units), the CQI of the transmission level on the channel corresponding to some time units is used to characterize the CQI of the transmission level on the channel corresponding to another part of the time units.

[0294] Those skilled in the art will understand that, in addition to differences in the channel position over the frequency domain, there will also be differences over time. Therefore, the weighting coefficients corresponding to the channel matrix of the same subband at different times may vary over time. Figure 10 shows the difference between the weighting coefficients corresponding to the channel matrices of the same subband at different TTIs. Taking the weighting coefficients corresponding to the channel matrix of TTI 1 as a benchmark, the distance of the weighting coefficients corresponding to the channel matrices of other TTIs relative to the benchmark can be determined. It can be understood that Figure 10 is equivalent to assuming that the channel matrix of TTI 1 is the channel matrix of the reference subband.

[0295] The curve shown in Figure 10 is obtained based on the following parameters and assumptions: CDL-A 100 ns, 1000 transmission time intervals (TTIs). It can be seen that as the TTI changes, the distance between the weighting coefficients corresponding to the channel matrix and the weighting coefficients corresponding to the channel matrix for TTI 1 also tends to increase. The distance between the weighting coefficients corresponding to the channel matrices for TTI 2 to TTI 500 and the weighting coefficients corresponding to the channel matrix for TTI 1 is smaller, less than or equal to 0.5. The distance between the limiting spectral density function of the channel matrix for TTI 1000 and the limiting spectral density function of the channel matrix for TTI 1 is larger, greater than 0.5.

[0296] It can be understood that the distance between the weighting coefficients corresponding to the channel matrices at two times can be used to represent the similarity between the weighting coefficients corresponding to the channel matrices at the two times. The longer the distance, the lower the similarity; the closer the distance, the higher the similarity.

[0297] Therefore, the network device may also predetermine a CQI feedback cycle, which may include multiple time units, such as a reference time unit and at least one target time unit. Based on this feedback cycle, the terminal may measure and feedback the stream-level CQI of the reference channel, without having to measure and feedback the stream-level CQI of the corresponding channel in each time unit. In other words, the network device configures the CQI feedback cycle before step 210.

[0298] Optionally, the method further includes step 950: the network device sends second configuration information to the terminal, where the second configuration information is used to configure one or more of the following: a CQI feedback period, a reference time unit within each feedback period, or multiple basis functions corresponding to each feedback period. Accordingly, the terminal receives the second configuration information from the network device.

[0299] It should be noted that the CQI feedback period mentioned in this article mainly refers to the feedback period of the stream-level CQI of the reference channel. Therefore, the CQI feedback period does not limit the feedback period of other channel measurement results, such as the feedback period of other parameters (such as precoding matrix indicator (PMI), rank indicator (RI), etc.) defined in the current 3GPP standard. Of course, this application does not limit the size relationship between the feedback period of the stream-level CQI and the feedback period of other parameters. The two can be the same or different. The CQI feedback period can also be variable. For example, the network device can determine the feedback period based on the stream-level CQI or other channel measurement results previously fed back by the terminal, and configure the CQI feedback period for the terminal through the second configuration information. The CQI feedback period can be fixed, such as predefined by the protocol, or the network device can no longer change after being configured through signaling. Therefore, the network device does not necessarily configure the CQI feedback period every time it sends the second configuration information, or the network device does not necessarily send the second configuration information before each time it sends the first reference signal.

[0300] The terminal may determine the reference time unit and the target time unit based on the feedback cycle configured by the second configuration information. For example, the terminal may determine the reference time unit and the target time unit based on a preset rule, where the preset rule may be, for example, that the first time unit in the feedback cycle is the reference time unit, and the other time units are the target time units. For another example, the network device may configure the reference time unit in the CQI feedback cycle through the second configuration information, that is, the second configuration information is also used to configure the reference time unit in the CQI feedback cycle.

[0301] The multiple basis functions used in different CQI feedback cycles can be the same or different. For example, the multiple basis functions can be fixed, such as predefined by a protocol; the multiple basis functions can also be variable, such as when a network device configures multiple basis functions for each feedback cycle through second configuration information, etc., without limitation.

[0302] It should be noted that when the network device configures the CQI feedback cycle, the reference time unit of each feedback cycle, or any one of the corresponding multiple basis functions through the second configuration information, it does not mean that the network device indicates any one of the above multiple items in each second configuration information sent. As long as the terminal can determine one or more of the above multiple items based on the second configuration information from the network device, it can be considered that the second configuration information is used to configure one or more of the above multiple items. In other words, this application does not limit how the network device configures the CQI feedback cycle, the reference time unit of each feedback cycle, and the corresponding multiple basis functions.

[0303] FIG11 exemplarily shows a process of determining a CQI feedback cycle by a network device. The process illustrated in FIG11 may be performed before step 910 of method 900.

[0304] As shown in FIG. 11 , the process includes steps 1110 to 1150 .

[0305] In step 1110, the network device sends a third reference signal, where the third reference signal is transmitted over multiple time units. Correspondingly, the terminal receives the third reference signal.

[0306] The third reference signal may be a reference signal sent by the network device before the first reference signal described in step 910, such as a CSI-RS or other signal that can be used to implement the same or similar functions.

[0307] In addition, unlike the first reference signal, the transmission of the third reference signal may continue for a longer time in the time domain. In other words, the network device may repeatedly transmit the third reference signal over multiple time domain units.

[0308] For more detailed processes of sending and receiving the third reference signal, please refer to the existing technology and will not be described in detail here.

[0309] In step 1120 , the terminal determines a weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the plurality of time units based on the received third reference signal.

[0310] The terminal can estimate the channel matrix of each time unit in multiple time units based on the received third reference signal, and then calculate the limiting spectral density function of the channel matrix of each time unit, and determine the weighting coefficient corresponding to the channel matrix of each time unit based on multiple common basis functions.

[0311] The terminal may receive the third reference signal on one or more subbands and determine, for each of the one or more subbands, a weighting coefficient corresponding to a channel in each of a plurality of time units. The one or more subbands may be subbands included in the frequency domain resources used by the network device to transmit the third reference signal, which is not limited in this application.

[0312] In one possible implementation, the multiple basis functions are pre-configured to the terminal by the network device via configuration information. Optionally, before step 1110, the method further includes step 1130: the network device sends fifth configuration information to the terminal, where the fifth configuration information is used to configure the multiple basis functions. Accordingly, the terminal receives the fifth configuration information from the network device.

[0313] It should be understood that the fifth configuration information has similar functions to the fourth configuration information in the process shown in Figure 7. The multiple basis functions configured by the network device through the fifth configuration information and the multiple basis functions configured through the fourth configuration information can be the same or different, without limitation.

[0314] In another possible implementation, the multiple basis functions are pre-stored by the terminal. For example, the terminal may locally store multiple basis functions pre-defined by the protocol, or locally store multiple basis functions configured by the network device during the last channel estimation or channel measurement, or independently determine multiple basis functions based on the last channel estimation or channel measurement. This application is not limited to this.

[0315] The specific process of the terminal determining the weighting coefficient corresponding to the channel matrix of each time unit based on the received third reference signal can be found in step 1 of the above algorithm and will not be repeated here.

[0316] It should be understood that the multiple basis functions on which the terminal determines the weighting coefficients corresponding to the extreme spectral density function of the channel matrix of each time unit in step 1120 may be the same as or different from the multiple basis functions used in the above method 200, and this application does not limit this.

[0317] In step 1140, the terminal sends third indication information to the network device, where the third indication information is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel in each of the multiple time units. Accordingly, the network device receives the third indication information from the terminal.

[0318] The terminal may feed back the calculated weighting coefficients corresponding to the channel matrices of each subband in each time unit to the network device via third indication information, thereby facilitating the network device to determine the time period over which the weighting coefficients of the channel matrices of each subband change minimally and the time period after which they change significantly.

[0319] For a more detailed process of the terminal sending the third indication information to the network device, please refer to the relevant description in step 230 of the method 200, which will not be repeated here.

[0320] In step 1150, the network device determines one or more CQI feedback cycles based on the third indication information.

[0321] The network device may determine, along the time domain direction, for example, in chronological order, using the weighting coefficient corresponding to the channel matrix of a certain subband in a certain time unit (for example, the first time unit among the multiple time units) as a reference, and, based on the weighting coefficient corresponding to the channel matrix of the subband in each time unit among the multiple time units indicated by the third indication information, which time units among the multiple time units have a distance (for example, a Euclidean distance) between the weighting coefficient of the channel matrix of the subband and the weighting coefficient of the channel matrix of the first time unit that does not exceed a second preset threshold. This may determine the size and position of the CQI feedback cycle.

[0322] It should be understood that the second preset threshold for determining the CQI feedback cycle in this embodiment and the first preset threshold for determining the subband grouping in the process shown in Figure 7 above can be the same threshold value or different threshold values, and this application does not limit this.

[0323] Figure 12 is a schematic diagram of the CQI feedback cycle provided by an embodiment of the present application. As shown in the figure, the terminal can perform channel measurement and feedback of the reference channel at a time interval T2 (or, at a time interval of length T2), so as to feed back the stream-level CQI of the reference channel to the network device. Optionally, the terminal can also feed back relevant parameters of the target channel and the reference channel while feeding back the stream-level CQI of the reference channel. The terminal can perform feedback of relevant parameters at a time interval T1 (or, at a time interval of length T1). It can be seen that T2 can be greater than T1, for example, the duration of a T2 can be the duration of one or more T1s.

[0324] In other words, the sending of the first indication information mentioned in step 930 of the aforementioned method 900 can be achieved through multiple sending operations. For example, the information for indicating the channel measurement result of the reference channel is sent at a time interval of T2, and the information for indicating the relevant parameters of the target channel and the reference channel (such as the ratio corresponding to each transmission layer) is sent at a time interval of T1. For another example, the information for indicating the channel measurement result of the reference channel and the weighting coefficient corresponding to the reference channel is sent at a time interval of T2, and the information for the weighting coefficient corresponding to the target channel is sent at a time interval of T1. Correspondingly, the reception of the first indication information can also be achieved through multiple receiving operations, which will not be repeated here.

[0325] Based on the above scheme, the network equipment can determine the CQI feedback cycle based on the difference between the weighting coefficients corresponding to the extreme spectral density function of the channel matrix in different time units. In each CQI feedback cycle, the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is small, that is, the channel similarity is high. Therefore, the CQI corresponding to each transmission layer on the target channel obtained based on the CQI corresponding to each transmission layer on the reference channel and the related parameter estimation is more accurate, which is conducive to more reasonable scheduling on the network side and improves spectrum efficiency.

[0326] Those skilled in the art will appreciate that when terminals at different locations receive reference signals, the estimated channel matrices differ due to the different channels traversed by the reference signals. Consequently, the weighting coefficients corresponding to the channel matrices determined by terminals at different locations also differ. Figure 13 illustrates the differences in weighting coefficients corresponding to the channel matrices estimated by terminals at different locations.

[0327] The curve shown in Figure 13 is based on the following parameters and assumptions: CDL-A 100 ns, 27 terminals (UE 1 to UE 27 in the figure). Figure 13 uses the weighting coefficients corresponding to the channel matrix estimated by UE 1 as a reference, and can be used to determine the distance of the weighting coefficients corresponding to the channel matrices estimated by other UEs relative to this reference. It can be understood that Figure 13 is equivalent to assuming that the channel matrix estimated by UE 1 is the channel matrix for the reference subband.

[0328] It can be seen that the distances (such as Euclidean distance) between the weighting coefficients corresponding to the channel matrices estimated by UE 7 and UE 27 respectively and the weighting coefficients corresponding to the channel matrix estimated by UE 1 are larger and greater than 1; the distance (such as Euclidean distance) between the weighting coefficients corresponding to the channel matrix estimated by UE 17 and the weighting coefficients corresponding to the channel matrix estimated by UE 1 is smaller and less than 1.

[0329] Figure 14 shows the locations of different UEs, UE 1 through UE 27, from the network's perspective. Figure 14 uses the azimuth angle of departure (AoD) as the horizontal coordinate and the zenith angle of departure (ZoD) as the vertical coordinate, illustrating the angles of electromagnetic waves transmitted to different terminals from the network's perspective. As shown in Figure 14, UE1's AoD is -60° and its ZoD is 90°, while UE17's AoD is -40° and its ZoD is 120°. These two terminals are relatively close in spatial distance, and the distances corresponding to the large weighting coefficients in their estimated channel matrices are also relatively close.

[0330] Based on the differences in the channel matrices estimated by terminals at different locations, network equipment can evaluate the possible interference if these terminals use the same time-frequency resources based on the differences between the weighting coefficients corresponding to the channel matrices estimated by terminals at different locations, thereby providing a basis for the network equipment to perform multi-user scheduling.

[0331] Figure 15 is another schematic flow chart of a communication method provided by an embodiment of the present application. As shown in Figure 15, the method 1500 may include steps 1510 to 1560. Each step in the method 1500 is described in detail below.

[0332] In step 1510, the network device sends a fourth reference signal. Correspondingly, multiple terminals receive the fourth reference signal.

[0333] The fourth reference signal may be a reference signal for channel measurement sent by the network device, such as a CSI-RS or other signal that can be used to implement the same or similar functions. Multiple terminals may exist within the signal coverage range of the network device, and each of these multiple terminal devices may receive the fourth reference signal sent by the network device. In other words, the fourth reference signal received by these multiple terminal devices is a reference signal transmitted using the same time-frequency resources.

[0334] For more detailed processes of sending and receiving the fourth reference signal, please refer to the existing technology and will not be described in detail here.

[0335] It should be noted that in the processes shown in Figures 2, 7, and 10 above, each process is described using only one terminal as an example. This does not mean that there is only one terminal that receives the first, second, and third reference signals. Since each terminal that receives the reference signal can be executed based on the process provided in Figures 2, 7, or 10 above, the above is described using one terminal as an example without loss of generality.

[0336] In step 1520, each of the plurality of terminals determines, based on the received fourth reference signal, a weighting coefficient corresponding to a limiting spectral density function of a channel matrix estimated by the terminal.

[0337] Taking any one of the multiple terminals as an example, the terminal can perform channel estimation based on the received fourth reference signal to obtain a channel matrix, and then obtain corresponding weighting coefficients based on the channel matrix. The process of the terminal performing channel estimation based on the fourth reference signal and calculating the weighting coefficients corresponding to the channel matrix can be found in step 1 of the algorithm above and is not further described.

[0338] In step 1530, each of the multiple terminals sends fourth indication information to the network device, where the fourth indication information is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel matrix. Accordingly, the network device receives the fourth indication information from each of the multiple terminals.

[0339] Still taking any one of the multiple terminals as an example, the terminal may feed back the calculated weighting coefficient corresponding to the channel matrix to the network device through fourth indication information.

[0340] For the network device, it can receive fourth indication information from multiple terminal devices within its signal coverage, which is used to indicate the weighting coefficients corresponding to the channel matrices estimated by each of the terminal devices.

[0341] For a more detailed process of the terminal sending the fourth indication information to the network device, please refer to the relevant description in step 230 of the method 200, which will not be repeated here.

[0342] In step 1540, the network device determines a candidate terminal set for MU scheduling according to the fourth indication information from each terminal in the multiple terminals.

[0343] The candidate terminal set for MU scheduling includes one or more candidate terminals, and the one or more candidate terminals can share the same time-frequency resources for communication within the signal coverage range of the network device.

[0344] It can be understood that the channel matrices estimated by the above-mentioned multiple terminals correspond to the same time-frequency resources. If the channel matrices estimated by two terminals differ significantly, it means that there are significant differences between the channels experienced by the fourth reference signal from the network device to each terminal. In this case, the two terminals may be in different locations or are far apart. If the network device uses the same time-frequency resources to schedule the two terminals, the mutual interference may be small. Conversely, if the channel matrices estimated by the two terminals differ slightly, it means that there is little difference between the channels experienced by the fourth reference signal from the network device to each terminal. In this case, the two terminals may be in the same location or are close together. If the network device uses the same time-frequency resources to schedule the two terminals, the mutual interference may be large.

[0345] Therefore, the network device can calculate the distance (e.g., Euclidean distance) between each of the multiple terminals based on the weighting coefficient indicated by the fourth indication information from each terminal, and then determine the candidate terminals for MU scheduling based on the distances between the weighting coefficients corresponding to the multiple terminals. It is understandable that the number of candidate terminals determined for MU scheduling can be one or more. The set consisting of candidate terminals is referred to herein as a candidate terminal set. When the candidate terminal set includes multiple candidate terminals, the distance between the corresponding weighting coefficients of any two of the multiple candidate terminals is greater than a third preset threshold.

[0346] It should be noted that the basis for the network device to determine terminals for MU scheduling is not limited to the distance between the weighted coefficients described above. This embodiment only provides a process for the network device to determine a set of candidate terminals. The network device can further screen within this set of candidate terminals to determine terminals that can share the same time-frequency resources. In other words, the process of the network device determining the set of candidate terminals is similar to an initial screening of terminals available for MU scheduling by the network device. Terminals that are located close or relatively close are screened out based on the distance between the weighted coefficients, thereby determining terminals available for MU scheduling within the small range of the candidate terminal set.

[0347] It should be understood that the third preset threshold used to determine the candidate terminal set in this embodiment and the first preset threshold used to determine the subband grouping in Figure 7 or the second preset threshold used to determine the CQI period in Figure 11 can be the same threshold value or different threshold values, and this application does not limit this.

[0348] Optionally, before step 1510, the method further includes step 1550: the network device sends sixth configuration information to multiple terminals, where the sixth configuration information is used to indicate the time-frequency resources of the fourth reference signal. Accordingly, each of the multiple terminals receives the sixth configuration information.

[0349] In this embodiment, the network device can determine the candidate terminals for MU scheduling based on the differences between the weighting coefficients corresponding to the channel matrices of each terminal. Therefore, the time-frequency resources used to transmit the fourth reference signal can be, for example, part or all of the time-frequency resources used for MU scheduling.

[0350] Alternatively, each terminal may also receive the fourth reference signal on the allocated bandwidth, or receive the fourth reference signal through reference signal resources, etc., which is not limited in this application.

[0351] As mentioned above, when the terminal determines the corresponding weighting coefficient according to the channel matrix, it is determined based on multiple basis functions. That is, the estimated limit spectral density function of the channel matrix is ​​represented by the weighted sum of multiple basis functions, so that the weighting coefficient of the channel matrix can be obtained.

[0352] For multiple terminals, the multiple basis functions may be common to the multiple terminals, or in other words, shared by the multiple terminals. Therefore, the multiple terminals may determine the weighting coefficients corresponding to their respective channel matrices based on the common multiple basis functions.

[0353] In one possible implementation, the multiple basis functions are preconfigured by the network device to the terminal via configuration information. Optionally, before step 1510, the method further includes step 1560: the network device sends seventh configuration information to the multiple terminals, where the seventh configuration information is used to configure the multiple basis functions. Accordingly, each of the multiple terminals receives the seventh configuration information from the network device.

[0354] In another possible implementation, the multiple basis functions are pre-stored by each terminal. For example, each terminal may pre-store multiple basis functions pre-defined by the protocol locally. This application does not limit this.

[0355] It should be understood that although Figure 15 only shows the interaction between one terminal and the network device, this should not constitute any limitation to this application. Multiple terminals within the signal coverage of the network device can execute the various steps executed by the terminal in Figure 15, and no further details will be given.

[0356] Based on the above scheme, the network device can obtain the weighting coefficients corresponding to the channel matrix fed back by each terminal within its signal coverage range, and then determine the candidate terminals for MU scheduling based on the distance between the weighting coefficients corresponding to multiple terminals. Since the greater the distance between the weighting coefficients, the less similar the channels are, that is, the terminals may be located in different locations or farther apart, and the interference is also smaller, which is conducive to reducing interference between multiple terminals sharing the same time-frequency resources. In addition, after the network device determines the candidate terminal set, it can further determine the terminals that can be used for MU scheduling from the candidate terminal set. That is, it is not necessary to determine the terminals that can be used for MU scheduling from all terminals within the signal coverage range of the network device. Therefore, the network device can reduce the amount of calculation and processing complexity.

[0357] It should be understood that in the multiple embodiments shown above in conjunction with the accompanying drawings, the sequence numbers of the steps do not imply the order of execution, and the order of execution of the steps should be determined by their functions and internal logic.

[0358] The method provided by the embodiment of the present application is described in detail above with reference to a plurality of drawings. The device provided by the embodiment of the present application is described below with reference to the drawings.

[0359] Figure 16 shows a possible exemplary block diagram of a communication device involved in embodiments of the present application. As shown in Figure 16, communication device 1600 may include modules or units corresponding to the above-mentioned method embodiments. In one possible design, communication device 1600 includes: a processing unit 1620 and a communication unit 1630. Optionally, communication device 1600 may also include a storage unit 1610 for storing device program code and / or data.

[0360] (1) The communication device 1600 may be the terminal-side device in the above-mentioned embodiment, for example, a terminal or a communication module in the terminal, or a circuit or chip in the terminal responsible for the communication function.

[0361] For example, in one embodiment, the communication unit 1630 is used to receive a first reference signal, which is transmitted on a reference channel and a target channel; the processing unit 1620 is used to determine a channel measurement result and related parameters of the reference channel based on the received first reference signal; the channel measurement result of the reference channel includes: a CQI corresponding to each transmission layer in one or more transmission layers on the reference channel, related parameters are used to indicate the relationship between the limiting spectral density function of the target channel and the limiting spectral density function of the reference channel, the limiting spectral density function of the reference channel is used to indicate the singular values ​​corresponding to each transmission layer in one or more transmission layers on the reference channel, the limiting spectral density function of the target channel is used to indicate the singular values ​​corresponding to each transmission layer in one or more transmission layers on the target channel, the singular values ​​corresponding to the first transmission layer are used to determine the CQI corresponding to the first transmission layer, and the first transmission layer is any one of the one or more transmission layers; the communication unit 1630 is also used to send first indication information, which is used to indicate the channel measurement result and related parameters of the reference channel.

[0362] In one possible design, the communication unit 1630 is also used to receive first configuration information, which is used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit within each first frequency band, or multiple basis functions corresponding to each first frequency band.

[0363] In one possible design, the communication unit 1630 is also used to receive a second reference signal, which is transmitted on multiple frequency domain units; the processing unit 1620 is also used to determine the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units based on the received second reference signal, and the weighting coefficients corresponding to the extreme spectral density functions of the channels of the multiple frequency domain units are respectively determined based on multiple common basis functions, and are used to determine one or more first frequency bands within a preset bandwidth; the communication unit 1630 is also used to send second indication information, which is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units.

[0364] In one possible design, the communication unit 1630 is also used to receive second configuration information, which is used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit within each feedback cycle, and multiple basis functions corresponding to each feedback cycle.

[0365] In one possible design, the communication unit 1630 is also used to receive a third reference signal, which is transmitted over multiple time units; the processing unit 1620 is also used to determine, based on the received third reference signal, a weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units, and the weighting coefficients corresponding to the channels in the multiple time units are determined based on multiple common basis functions, and are used to determine one or more feedback cycles of the CQI; the communication unit 1630 is also used to send third indication information, which is used to indicate the weighting coefficient corresponding to the channel of each time unit in the multiple time units.

[0366] It should be understood that the processing unit 1620 may be used to execute step 220 in the method embodiment shown in FIG2 , or step 720 in the method embodiment shown in FIG7 , or step 920 in the method embodiment shown in FIG9 , or step 1120 in the method embodiment shown in FIG11 , or step 1520 in the method embodiment shown in FIG15 . The communication unit 1630 may be used to execute steps 210, 230, and 250 in the method embodiment shown in FIG2 , or steps 710, 730 to 750 in the method embodiment shown in FIG7 , or steps 910, 930 to 950 in the method embodiment shown in FIG9 , or steps 1110, 1130, and 1140 in the method embodiment shown in FIG11 , or steps 1510, 1530, 1550, and 1560 in the method embodiment shown in FIG15 .

[0367] It should be understood that the specific process of each unit executing the above corresponding process has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0368] In one possible design, when the communication device 1600 is a terminal or a communication module in a terminal, the functions of the processing unit 1620 may be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-chip (SoC) chip or SIP chip containing a modem core. The functions of the communication unit 1630 may be implemented by a transceiver circuit.

[0369] In one possible design, when the communication device 1600 is a circuit or chip responsible for communication functions in a terminal, such as a modem chip or a system-on-chip (SoC) chip or SIP chip containing a modem core, the functions of the processing unit 1620 can be implemented by a circuit system including one or more processors or processor cores in the aforementioned chip. The functions of the communication unit 1630 can be implemented by an interface circuit or data transceiver circuit on the aforementioned chip.

[0370] In another embodiment, the communication unit 1630 is used to receive a fourth reference signal; the processing unit 1620 is used to determine a weighting coefficient corresponding to the extreme spectral density function of the channel based on the received fourth reference signal, wherein the extreme spectral density function of the channel is a weighted sum of multiple basis functions, and the multiple basis functions are basis functions common to multiple terminals; the communication unit 1630 is also used to send fourth indication information, which is used to indicate the above-mentioned weighting coefficient.

[0371] (2) The communication device 1600 may be a network-side device in the above-mentioned embodiment, such as a network device or a communication module in a network device, or a circuit or chip in charge of the communication function in the network device.

[0372] For example, in one embodiment, the communication unit 1630 is used to send a first reference signal, which is transmitted on a reference channel and a target channel; the communication unit 1630 is also used to receive first indication information, where the first indication information is used to indicate a channel measurement result and related parameters of the reference channel, where the channel measurement result of the reference channel includes a CQI corresponding to each of one or more transmission layers on the reference channel, and related parameters are used to indicate parameters of a relationship between the CQI of the target channel and the CQI of the reference channel; the limiting spectral density function of the reference channel is used to indicate a singular value corresponding to each of one or more transmission layers on the reference channel; the limiting spectral density function of the target channel is used to indicate a singular value corresponding to each of one or more transmission layers on the target channel; the singular value corresponding to the first transmission layer is used to determine a CQI corresponding to the first transmission layer, where the first transmission layer is any one of the one or more transmission layers; and the processing unit 1620 is used to determine a CQI corresponding to each of the one or more transmission layers on the target channel based on the channel measurement result and related parameters of the reference channel.

[0373] In one possible design, the communication unit 1630 is also used to send first configuration information, which is used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit within each first frequency band, or multiple basis functions corresponding to each first frequency band.

[0374] In one possible design, the communication unit 1630 is also used to send a second reference signal, which is transmitted on multiple frequency domain units; the communication unit 1630 is also used to receive second indication information, which is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units; the processing unit 1620 is also used to determine one or more first frequency bands based on the second indication information.

[0375] In one possible design, the communication unit 1630 is also used to send second configuration information, which is used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit within each feedback cycle, and multiple basis functions corresponding to each feedback cycle.

[0376] In one possible design, the communication unit 1630 is also used to send a third reference signal, which is transmitted over multiple time units; the communication unit 1630 is also used to send third indication information, which is used to indicate the weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units; the processing unit 1620 is also used to determine one or more feedback cycles of the CQI based on the third indication information.

[0377] In another embodiment, the communication unit 1630 is used to receive a fourth reference signal; the processing unit 1620 is used to determine a weighting coefficient corresponding to the extreme spectral density function of the channel based on the received fourth reference signal, wherein the extreme spectral density function of the channel is a weighted sum of multiple basis functions, and the multiple basis functions are basis functions common to multiple terminals; the communication unit 1630 is also used to send fourth indication information, which is used to indicate the above-mentioned weighting coefficient.

[0378] It should be understood that the processing unit 1620 may be configured to execute step 240 in the method embodiment shown in FIG2 , step 760 in the method embodiment shown in FIG7 , step 940 in the method embodiment shown in FIG9 , step 1150 in the method embodiment shown in FIG11 , or step 1540 in the method embodiment shown in FIG15 . The communication unit 1630 may be configured to execute steps 210, 230, and 250 in the method embodiment shown in FIG2 , steps 710, 730 to 750 in the method embodiment shown in FIG7 , steps 910, 930 to 950 in the method embodiment shown in FIG9 , steps 1110, 1130, and 1140 in the method embodiment shown in FIG11 , or steps 1510, 1530, 1550, and 1560 in the method embodiment shown in FIG15 .

[0379] It should be understood that the specific process of each unit executing the above corresponding process has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0380] In one possible design, when the communication device 1600 is a network device or a communication module within a network device, the functions of the processing unit 1620 may be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-chip (SoC) chip or SIP chip containing a modem core. The functions of the communication unit 1630 may be implemented by a transceiver circuit.

[0381] In one possible design, when the communication device 1600 is a circuit or chip responsible for communication functions in a network device, such as a modem chip or a system-on-chip (SoC) chip or SIP chip containing a modem core, the functions of the processing unit 1620 can be implemented by a circuit system including one or more processors or processor cores in the aforementioned chip. The functions of the communication unit 1630 can be implemented by an interface circuit or data transceiver circuit on the aforementioned chip.

[0382] It should also be understood that the communication unit 1630 in the communication device 1600 can also be referred to as a transceiver unit. The communication unit 1630 may include a transmitting module but not a receiving module. Alternatively, the communication unit 1630 may include a receiving module but not a transmitting module. The specific implementation depends on whether the above-mentioned solution executed by the communication device 1600 includes both transmitting and receiving actions. The receiving module may be used to perform the receiving action in the above-mentioned solution, and the transmitting module may be used to perform the transmitting action in the above-mentioned solution.

[0383] It is understandable that the division of units in the above-mentioned device is merely a division of logical functions, and each function may correspond to a functional unit, or two or more functions may be integrated into one functional unit. In actual implementation, all or part of the units may be integrated into one physical entity, or distributed across different physical entities. In addition, the above-mentioned functional units may be implemented in the form of hardware, software, or a combination of hardware and software. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0384] In one example, the functional unit in any of the above devices can be one or more integrated circuits configured to implement the above method, such as: one or more application specific integrated circuits (ASICs), or, one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or, one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0385] In an example, the storage unit 1610 may include a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory and / or a register.

[0386] Figure 17 shows another possible exemplary block diagram of a communication device involved in the embodiments of the present application. As shown in Figure 17, communication device 1700 includes a processor 1710. Processor 1710 can be used to execute computer programs or instructions in memory to implement the steps performed by the terminal or the steps performed by the network device in the method embodiments shown in Figures 2, 7, 9, 11, or 15.

[0387] Optionally, the communication device 1700 includes one or more processors 1710.

[0388] Optionally, the apparatus 1700 further includes a communication interface 1720. The processor 1710 and the communication interface 1720 are coupled to each other. It is understood that the communication interface 1720 may be a transceiver or an input / output interface.

[0389] Optionally, the communication device 1700 may further include a memory 1730 for storing computer programs or instructions executed by the processor 1710. Optionally, the memory 1730 is also used to store input data required by the processor 1710 to execute the computer program or instructions, or to store data generated after the processor 1710 executes the instructions. Optionally, the memory 1730 may be integrated with the processor 1710 or provided separately.

[0390] As an embodiment, the processor 1710 is configured to execute the functions of the aforementioned processing unit, such as step 220 in the method embodiment shown in FIG. 2 , step 720 in the method embodiment shown in FIG. 7 , step 920 in the method embodiment shown in FIG. 9 , step 1120 in the method embodiment shown in FIG. 11 , or step 1520 in the method embodiment shown in FIG. 15 . The communication interface 1720 is configured to execute the functions of the aforementioned communication unit. Whether the communication interface 1720 is configured to transmit or receive can be determined by the scheme executed by the communication device 1700. For example, the communication interface 1720 may be configured to execute steps 210, 230, and 250 in the method embodiment shown in FIG. 2 , steps 710 and steps 730 to 750 in the method embodiment shown in FIG. 7 , steps 910 and steps 930 to 950 in the method embodiment shown in FIG. 9 , steps 1110, 1130, and 1140 in the method embodiment shown in FIG. 11 , or steps 1510, 1530, 1550, and 1560 in the method embodiment shown in FIG. 15 .

[0391] As another embodiment, the processor 1710 is configured to execute the functions of the aforementioned processing unit, such as step 240 in the method embodiment shown in FIG2 , step 760 in the method embodiment shown in FIG7 , step 940 in the method embodiment shown in FIG9 , step 1150 in the method embodiment shown in FIG11 , or step 1540 in the method embodiment shown in FIG15 . The communication interface 1720 is configured to execute the functions of the aforementioned communication unit. Whether the communication interface 1720 is configured to transmit or receive can be determined by the method executed by the communication device 1700. For example, it can be configured to execute steps 210, 230, and 250 in the method embodiment shown in FIG2 , steps 710 and steps 730 to 750 in the method embodiment shown in FIG7 , steps 910 and steps 930 to 950 in the method embodiment shown in FIG9 , steps 1110, 1130, and 1140 in the method embodiment shown in FIG11 , or steps 1510, 1530, 1550, and 1560 in the method embodiment shown in FIG15 .

[0392] It should be understood that the specific process of each unit executing the above corresponding process has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0393] When the communication device 1700 is a chip used in a terminal, the chip implements the functions of the terminal in the above method embodiments. The chip of the terminal receives signals from other modules in the terminal (such as a radio frequency module or antenna), and the signals may be sent to the terminal by a network device; or the chip of the terminal sends signals to other modules in the terminal (such as a radio frequency module or antenna), and the signals may be sent to the network device by the terminal.

[0394] When the communication device 1700 is a chip used in a network device, the chip implements the functions of the network device in the above method embodiments. The chip of the network device receives signals from other modules in the network device (such as a radio frequency module or antenna), and the signals may be sent by the terminal to the network device; or the chip of the network device sends signals to other modules in the network device (such as a radio frequency module or antenna), and the signals may be sent by the network device to the terminal.

[0395] It is understood that when the communication device 1700 is a terminal or network device, the communication interface 1720 may be a transceiver, specifically including a transmitter and a receiver, where the transmitter is used to transmit signals and the receiver is used to receive signals. When the communication device 1700 is a chip used in a terminal or network device, the communication interface 1720 may be an input / output circuit, a bus, a module, a pin, or other type of communication interface, where the input circuit of the input / output circuit can be used for receiving, and the output interface can be used for transmitting.

[0396] It should be understood that in the communication device 1700 shown in Figure 17, the processor 1710 may correspond to the processing unit 1620 in the above communication device 1600, the communication interface 1720 may correspond to the communication unit 1630 in the above communication device 1600, and the memory 1730 may correspond to the storage unit 1610 in the above communication device 1600.

[0397] It should also be understood that the coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which can be electrical, mechanical, or other forms, and is used for information exchange between devices, units, or modules. The processor 1710 can operate in conjunction with the communication interface 1720 and the memory 1730. The specific connection medium between the processor 1710, the communication interface 1720, and the memory 1730 is not limited in the embodiments of the present application.

[0398] Optionally, the processor 1710, the communication interface 1720, and the memory 1730 are interconnected via a bus. The bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, and the like.

[0399] Figure 18 is a schematic diagram of the structure of a terminal 1800 provided in an embodiment of the present application. This terminal 1800 may correspond to the terminal shown in Figure 1 and is used to implement the operations of the terminal in the above embodiments. As shown in Figure 18, the terminal includes: one or more antennas 1818, a radio frequency processing system 1820, and a processor system 1830.

[0400] In the downlink direction, the RF processing system 1820 receives RF signals through the antenna 1810 and sends the processed signals to the processor system 1830 for further processing. In the uplink direction, the processor system 1830 processes the terminal side information and sends it to the RF processing system 1820. The RF processing system 1820 processes the signal and sends it through the antenna 1818.

[0401] In one example, the RF processing system 1820, serving as the terminal's external communication interface, may include a radio frequency (RF) front end (RFFE) 1821 and an RF transceiver 1822. The RFFE 1821 primarily processes RF signals received by the antenna or to be transmitted through the antenna, including shaping, passband selection, and / or gain. It may include one or more components such as an RF switch, a duplexer, a filter, a power amplifier, an antenna tuner, and a low-noise amplifier. The RFFE 1821 may be a circuit system composed of multiple discrete components or integrated into one or more chips. The RF transceiver 1822 processes the RF signals received by the RFFE into baseband / IF signals for further processing by the processor system 1830, and processes the baseband / IF signals provided by the processor system 1830 into RF signals for transmission to the RFFE 1821. The baseband / IF signals transmitted between the transceiver 1820 and the processor system 1830 may be either digital or analog. The RF transceiver 1822 may be implemented by one or more chips, which are generally referred to as radio frequency integrated circuits (RFICs). Optionally, the RF transceiver 1822 may include a RF transmitter and a RF receiver. The RF transmitter is used to transmit signals, and the RF receiver is used to receive signals.

[0402] In one example, the processor system 1830 may include one or more processors for processing signals and executing one or more communication protocols, as well as memory 1836. In one example, the one or more processors include at least one baseband processor 1831 (also known as a modem processor). Memory 1836 is used to store data and / or computer programs or instructions. Optionally, the processor system 1830 may also include one or more application processors 1832 for processing the terminal operating system and application layer. Optionally, the processor system 1830 may also include a voice subsystem 1833, a multimedia subsystem 1834, an interface circuit 1835, and / or memory 1836. The voice subsystem 1833 is used to process voice signals, the multimedia subsystem 1834 is used to handle multimedia-related operations such as video encoding and decoding, image processing, etc., and the interface circuit 1835 is used to communicate with other terminal components, such as the display 1840, input device 1850, and memory 1860. The aforementioned components in the processor system 1830 may communicate with each other via a bus or communication interface circuit.

[0403] In one example, the processor system 1830 can be packaged into a processor chip, such as a SoC chip or a SIP chip. In another example, the processor system 1830 can be a system consisting of multiple chips, for example, the baseband processor 1831 can be packaged into a single chip, or it can be packaged into a single chip with part or all of the circuits of the radio frequency processing system.

[0404] In one example, the memory 1836 may be an on-chip memory, that is, located on the processor system 1830 chip. In one example, the memory 1860 may be an off-chip memory, that is, located outside the processor system 1830 chip.

[0405] In one example, the baseband processor 1831 may include one or more processor cores 18311, a memory 18312, and an interface circuit 18314. The one or more processor cores 18311 are configured to process signals and execute one or more communication protocols. The memory 18312 is configured to store at least a portion of corresponding computer programs or instructions and / or data. In one example, the one or more processor cores 18311 implement the relevant operations in the above-described method embodiments (e.g., determining the channel measurement results of the reference channel) by executing the computer programs or instructions stored in the memory 18312. In the present disclosure, the memory 18312 is used to store corresponding computer programs, instructions, and / or data. This can refer to the memory 18312 being used to store the entire corresponding computer program, instructions, and / or data for execution by the processor core 18311. It can also refer to the memory 18312 being used to store a portion of the corresponding computer program, instructions, and / or data, including the portion currently required to be executed by the processor 18311. The memory 18312 can store different portions of the computer program, instructions, and / or data multiple times for execution by the processor core 18311 to implement the relevant operations in the above-mentioned method embodiments. The interface circuit 18314 serves as a communication interface for communicating with other components, such as transmitting signals with the RF processing system 1820, communicating with other subsystems and related components of the processor system 1830 via a bus, such as transmitting data and control signals between the application processor 1832 and the voice subsystem 1833, and transmitting data or computer programs or instructions between the memory 1836 or the memory 1860. Optionally, in order to reduce the load of the processor core, a baseband signal processing circuit 18313 may be provided to implement at least part of the baseband signal processing, including signal demodulation, modulation, encoding or decoding.

[0406] In one example, the communication device provided in the present application may be a terminal 1800 , a communication module including a processor system 1830 and a radio frequency system 1820 , a processor system 1830 or a baseband processor 1831 .

[0407] In one example, the RF transceiver 1822 and the RF front end 1821 may also be packaged in one chip. In one example, the RF transceiver 1822, the RF front end 1821 and the baseband processor 1831 may also be packaged in one chip.

[0408] It should be understood that terminal 1800 shown in FIG18 is capable of implementing the various processes related to the terminal in the method embodiments shown in FIG2 , FIG7 , FIG9 , FIG11 , or FIG15 . The operations and / or functions of the various modules in terminal 1800 are respectively for implementing the corresponding processes in the aforementioned method embodiments. For details, please refer to the descriptions of the aforementioned method embodiments; to avoid repetition, detailed descriptions are omitted here.

[0409] Figure 19 is a schematic diagram of the structure of a network device provided in an embodiment of the present application, for example, a schematic diagram of the structure of a base station. The base station 1900 shown in Figure 19 can be used in the system shown in Figure 1 to perform the functions of the network device in the above-mentioned method embodiment. As shown in the figure, the base station 1900 may include one or more of the following: one or more (DU+RU) units 1910 and one or more CUs 1920. The CU 1920 can communicate with the next generation core (NG core). The DU may include at least one antenna 1911, at least one radio frequency unit 1912, at least one processor 1913, and at least one memory 1919. The DU portion is primarily used for transmitting and receiving radio frequency signals, converting radio frequency signals into baseband signals, and performing partial baseband processing. The CU 1920 may include at least one processor 1922 and at least one memory 1921. The CU 1920 and the DU may communicate via an interface. The control plane (CP) interface may be an Fs-C, such as F1-C, and the user plane (UP) interface may be an Fs-U, such as F1-U. The DU and RU can work together to implement the functions of the physical (PHY) layer. A DU can be connected to one or more RUs. The functions of the DU and RU can be configured in various ways according to the design. For example, the DU is configured to implement the baseband function, and the RU is configured to implement the mid-RF function. For another example, the DU is configured to implement the high-layer functions in the PHY layer, and the RU is configured to implement the low-layer functions and RF functions in the PHY layer. The high-layer functions in the PHY layer may include a part of the functions of the PHY layer, which is closer to the medium access control (MAC) layer, and the low-layer functions in the PHY layer may include another part of the functions of the PHY layer, which is closer to the mid-RF side.

[0410] The CU 1920 is primarily used for baseband processing and base station control. The DU and CU 1920 may be physically located together or physically separated, i.e., a distributed base station. The CU 1920 is the control center of the base station and may correspond to the processing unit in FIG11 or the processor in FIG12 , and may also be referred to as a processing unit, primarily for performing baseband processing functions. For example, the CU 1920 may be used to control the base station to execute the operational procedures for the access network device in the above-described method embodiment.

[0411] Specifically, baseband processing on the CU and DU can be divided according to the protocol layers of the wireless network. For example, the functions of the packet data convergence protocol (PDCP) layer and above are set in the CU, while the functions of the protocol layers below the PDCP, such as the radio link control (RLC) layer and the MAC layer, are set in the DU. For another example, the CU implements the functions of the radio resource control (RRC) layer and the PDCP layer, while the DU implements the functions of the RLC layer, MAC layer, and PHY layer.

[0412] In addition, optionally, the base station 1900 may include one or more radio frequency units (RUs), one or more DUs, and one or more CUs. The DU may include at least one processor 1913 and at least one memory 1919, the RU may include at least one antenna 1911 and at least one radio frequency unit 1912, and the CU may include at least one processor 1922 and at least one memory 1921.

[0413] In one example, the CU 1920 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 1921 and the processor 1922 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board. The DU may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 1919 and the processor 1913 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board.

[0414] It should be understood that base station 1900 shown in Figure 19 is capable of implementing the various processes involving network devices in the method embodiments shown in Figures 2, 7, 9, 11, or 15. The operations and / or functions of the various modules in base station 1900 are respectively for implementing the corresponding processes in the aforementioned method embodiments. For details, please refer to the descriptions of the aforementioned method embodiments; to avoid repetition, detailed descriptions are omitted here.

[0415] The BBU 1920 can be used to perform the actions implemented within the network device described in the previous method embodiments, while the RRU 1910 can be used to perform the actions described in the previous method embodiments in which the network device sends or receives data to or from the terminal. For details, please refer to the description in the previous method embodiments and will not be repeated here.

[0416] It will be understood that the processor, processor system, application processor, baseband processor, processor circuit or processor core in the embodiments of the present application may be collectively referred to as a processor, which may include a central processing unit (CPU), a digital signal processor (DSP), a microprocessor (MPU), a microcontroller (MCU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an artificial intelligence processor (AI processor) or a neural processing unit (NPU) One or more combinations thereof.

[0417] The aforementioned memory may include one or more of the following storage media: random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), phase-change memory (PCM), resistive RAM (ReRAM), magnetoresistive RAM (MRAM), ferroelectric RAM (FRAM), cache, register, read-only memory (ROM), flash memory, erasable programmable ROM (EPROM), hard disk, etc. In one example, the computer program or instructions for executing the aforementioned embodiments may be stored in a non-volatile memory, such as at least a portion of the aforementioned memory 1760 (e.g., one or more of ROM, flash memory, EPROM, or hard disk). When the terminal is running, the corresponding computer program or instructions can be partially or completely loaded into a memory with a faster transmission speed to the processor, such as at least a part of the above-mentioned memory 1736 and / or memory 17312 (such as one or more of RAM, SRAM, DRAM, PCM, RERAM, MRAM, FRAM, cache, or register), for execution by the processor to implement the steps in the above-mentioned method embodiments.

[0418] The present application also provides a communication system, which includes the aforementioned network device and terminal.

[0419] The present application also provides a computer program product, which includes: a computer program or instructions, which, when executed, enables a computer to execute the method executed by a terminal or the method executed by a network device in the embodiments shown in Figures 2, 7, 9, 11 or 15.

[0420] The present application also provides a computer-readable storage medium storing a computer program or instruction. When the computer program or instruction is executed, the computer executes the method executed by the terminal or the method executed by the network device in the embodiment shown in Figures 2, 7, 9, 11, or 15.

[0421] The terms "unit," "module," and the like used in this specification may be used to refer to a computer-related entity, hardware, firmware, a combination of hardware and software, software, or software in execution.

[0422] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, optical storage, etc.) that contain computer-usable program code.

[0423] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by a computer program or instruction. These computer programs or instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0424] These computer programs or instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0425] These computer programs or instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0426] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: receiving a first reference signal, where the first reference signal is transmitted on a reference channel and a target channel; Determine, based on the received first reference signal, a channel measurement result and related parameters of the reference channel, the channel measurement result of the reference channel including: a channel quality indicator (CQI) corresponding to each transmission layer in one or more transmission layers on the reference channel; the related parameters are used to indicate a relationship between a limiting spectral density function of the target channel and a limiting spectral density function of the reference channel; the limiting spectral density function of the reference channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the reference channel; the limiting spectral density function of the target channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the target channel; the singular value corresponding to a first transmission layer is used to determine a CQI corresponding to the first transmission layer, where the first transmission layer is any one of the one or more transmission layers; Sending first indication information, where the first indication information is used to indicate a channel measurement result of the reference channel and the related parameters.

2. The method according to claim 1, wherein The reference channel and the target channel correspond to different frequency domain units in the transmission resource of the first reference signal, the reference channel is a channel corresponding to the reference frequency domain unit, the target channel is a channel corresponding to the target frequency domain unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a first preset threshold; wherein, the extreme spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the extreme spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the extreme spectral density function is the weighting coefficient when the extreme spectral density function is represented by the weighted sum of multiple basis functions.

3. The method according to claim 2, wherein The method further comprises: Receive first configuration information, where the first configuration information is used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit for each first frequency band, or a plurality of basis functions corresponding to each first frequency band; wherein the first frequency band includes a plurality of frequency domain units, and among the plurality of frequency domain units, a distance between a weighting coefficient corresponding to the limiting spectral density function of a channel of any frequency domain unit other than the reference frequency domain unit and a weighting coefficient corresponding to the limiting spectral density function of the reference channel is less than or equal to the first preset threshold.

4. The method according to claim 3, wherein Before receiving the first configuration information, the method further includes: receiving a second reference signal, where the second reference signal is transmitted over a plurality of frequency domain units; Determining, based on the received second reference signal, a weighting coefficient corresponding to a limiting spectral density function of a channel of each of the multiple frequency domain units, wherein the weighting coefficients corresponding to the limiting spectral density functions of the channels of the multiple frequency domain units are respectively determined based on a plurality of common basis functions and are used to determine the one or more first frequency bands; Second indication information is sent, where the second indication information is used to indicate a weighting coefficient corresponding to the extreme spectral density function of the channel of each frequency domain unit in the multiple frequency domain units.

5. The method according to claim 1, wherein The reference channel and the target channel correspond to different time units in the transmission resource of the first reference signal, the reference channel is a channel corresponding to the reference time unit, the target channel is a channel corresponding to the target time unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a second preset threshold; wherein, the extreme spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the extreme spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the extreme spectral density function is the weighting coefficient when the extreme spectral density function is represented by the weighted sum of multiple basis functions.

6. The method according to claim 5, wherein The method further comprises: Receive second configuration information, where the second configuration information is used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit of each feedback cycle, or multiple basis functions corresponding to each feedback cycle; wherein the CQI feedback cycle includes multiple time units, and among the multiple time units, a distance between a weighting coefficient corresponding to the extreme spectral density function of the frequency channel of any time unit other than the reference time unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the second preset threshold.

7. The method according to claim 6, wherein Before receiving the second configuration information, the method further includes: receiving a third reference signal, wherein the third reference signal is transmitted over a plurality of time units; Determining, based on the received third reference signal, a weighting coefficient corresponding to a limiting spectral density function of a channel of each of the multiple time units, wherein the weighting coefficients corresponding to the limiting spectral density functions of the channels of the multiple time units are respectively determined based on a plurality of common basis functions, and are used to determine one or more feedback cycles of the CQI; Third indication information is sent, where the third indication information is used to indicate a weighting coefficient corresponding to the extreme spectral density function of the channel of each time unit in the multiple time units.

8. A communication method, characterized in that: include: Sending a first reference signal, where the first reference signal is transmitted on a reference channel and a target channel; receiving first indication information, where the first indication information is used to indicate a channel measurement result and related parameters of the reference channel, where the channel measurement result of the reference channel includes: a channel quality indicator (CQI) corresponding to each transmission layer in one or more transmission layers on the reference channel; the related parameters are used to indicate a relationship between a limiting spectral density function of the target channel and a limiting spectral density function of the reference channel; the limiting spectral density function of the reference channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the reference channel; the limiting spectral density function of the target channel is used to indicate a singular value corresponding to each transmission layer in the one or more transmission layers on the target channel; the singular values ​​corresponding to a first transmission layer are used to determine a CQI corresponding to the first transmission layer, where the first transmission layer is any one of the one or more transmission layers; Determine a CQI corresponding to each of the one or more transmission layers on the target channel according to the channel measurement result of the reference channel and the relevant parameters.

9. The method according to claim 8, wherein The reference channel and the target channel correspond to different frequency domain units in the transmission resource of the first reference signal, the reference channel is a channel corresponding to the reference frequency domain unit, the target channel is a channel corresponding to the target frequency domain unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a first preset threshold; wherein, the extreme spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the extreme spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the extreme spectral density function is the weighting coefficient when the extreme spectral density function is represented by the weighted sum of multiple basis functions.

10. The method according to claim 9, wherein The method further comprises: Send first configuration information, where the first configuration information is used to configure one or more of the following: one or more first frequency bands, a reference frequency domain unit for each first frequency band, or a plurality of basis functions corresponding to each first frequency band; wherein the first frequency band includes a plurality of frequency domain units, and among the plurality of frequency domain units, a distance between a weighting coefficient corresponding to the limiting spectral density function of a channel of any frequency domain unit other than the reference frequency domain unit and a weighting coefficient corresponding to the limiting spectral density function of the reference channel is less than or equal to the first preset threshold.

11. The method according to claim 10, wherein Before sending the first configuration information, the method further includes: Sending a second reference signal, where the second reference signal is transmitted over a plurality of frequency domain units; receiving second indication information, where the second indication information is used to indicate a weighting coefficient corresponding to a limit spectral density function of a channel of each frequency domain unit in the plurality of frequency domain units; The one or more first frequency bands are determined based on the second indication information.

12. The method according to claim 8, wherein The reference channel and the target channel correspond to different time units in the transmission resource of the first reference signal, the reference channel is a channel corresponding to the reference time unit, the target channel is a channel corresponding to the target time unit, and the distance between the weighting coefficient corresponding to the extreme spectral density function of the target channel and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to a second preset threshold; wherein, the extreme spectral density function of the reference channel is determined based on the channel matrix and singular value range of the reference channel, the extreme spectral density function of the target channel is determined based on the channel matrix and singular value range of the target channel, the channel matrix and singular value range of the reference channel are obtained based on the measurement of the first reference signal received on the reference channel, and the channel matrix and singular value range of the target channel are obtained based on the measurement of the first reference signal received on the target channel; the weighting coefficient corresponding to the extreme spectral density function is the weighting coefficient when the extreme spectral density function is represented by the weighted sum of multiple basis functions.

13. The method according to claim 12, wherein: The method further comprises: Send second configuration information, where the second configuration information is used to configure one or more of the following: one or more feedback cycles of CQI, a reference time unit of each feedback cycle, or multiple basis functions corresponding to each feedback cycle; wherein the CQI feedback cycle includes multiple time units, and among the multiple time units, the distance between the weighting coefficient corresponding to the extreme spectral density function of the frequency channel of any time unit other than the reference time unit and the weighting coefficient corresponding to the extreme spectral density function of the reference channel is less than or equal to the second preset threshold.

14. The method according to claim 13, wherein Before sending the second configuration information, the method further includes: sending a third reference signal, where the third reference signal is transmitted over a plurality of time units; receiving third indication information, where the third indication information is used to indicate a weighting coefficient corresponding to a limiting spectral density function of a channel of each time unit in the plurality of time units; Based on the third indication information, one or more feedback cycles of the CQI are determined.

15. The method according to any one of claims 2 to 7 and 9 to 14, characterized in that The relevant parameters include a weighting coefficient corresponding to the limiting spectral density function of the reference channel and a weighting coefficient corresponding to the limiting spectral density function of the target channel.

16. The method according to any one of claims 2 to 7 and 9 to 14, characterized in that The relevant parameters include a ratio corresponding to each of the one or more transmission layers, and the ratio corresponding to the first transmission layer is the ratio of an initial estimated value of a singular value of the first transmission layer on the target channel to an initial estimated value of a singular value of the first transmission layer on the reference channel, the initial estimated value of the singular value is determined based on an order statistic, the order statistic of the reference channel is determined based on the singular value range, the extreme spectral density function and the extreme spectral distribution function of the reference channel, and the order statistic of the target channel is determined based on the singular value range, the extreme spectral density function and the extreme spectral distribution function of the target channel.

17. A communication device, characterized in that: comprising a module or unit for performing the method as claimed in any one of claims 1 to 7, or claim 15 or 16 when referring to any one of claims 2 to 7, or comprising a module or unit for performing the method as claimed in any one of claims 8 to 14, or claim 15 or 16 when referring to any one of claims 9 to 14.

18. A communication device, characterized in that: The method comprises one or more processors configured to execute computer programs or instructions in a memory so that the communication device performs the method according to any one of claims 1 to 7, or claim 15 or 16 when referring to any one of claims 2 to 7, or the method according to any one of claims 8 to 14, or claim 15 or 16 when referring to any one of claims 9 to 14.

19. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instructions. When the computer program or instructions are executed by a computer, the method as described in any one of claims 1 to 7, or claim 15 or 16 when referring to any one of claims 2 to 7, or the method as described in any one of claims 8 to 14, or claim 15 or 16 when referring to any one of claims 9 to 14, is implemented.

20. A computer program product, characterized in that When a computer reads and executes the computer program product, the computer is caused to perform the method according to any one of claims 1 to 7, or claim 15 or 16 when referring to any one of claims 2 to 7, or the method according to any one of claims 8 to 14, or claim 15 or 16 when referring to any one of claims 9 to 14.

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