Method for sending channel state information (CSI), and communication apparatus

Abstract

The present application relates to the technical field of communications. Provided are a method for sending channel state information (CSI), and a communication apparatus. The method comprises: receiving a first reference signal, wherein a first frequency-domain density of a resource of the first reference signal is less than a second frequency-domain density of a resource of a second reference signal; and sending target channel state information (CSI), the target CSI comprising first CSI and / or second CSI, wherein the first CSI is CSI determined on the basis of the first reference signal and the second CSI, or the first CSI is CSI determined on the basis of the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal. By means of the method, time-frequency resources occupied by a CSI-RS can be reduced.

Description

Method and communication device for transmitting channel state information CSI

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on August 25, 2023, with application number 202311085451.5 and application name “Method and communication device for sending channel state information CSI”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a method and a communication device for sending channel state information (CSI). Background Art

[0003] Multiple Input and Multiple Output (MIMO) technology is a core technology of Long Term Evolution (LTE) systems and fifth-generation (5G) new radio (NR). Using MIMO technology, network equipment typically instructs terminal devices to detect the downlink wireless channel before sending data to them. For example, the network equipment sends a channel state information reference signal (CSI-RS), also known as a pilot signal, to the terminal device. The terminal device measures and evaluates the downlink wireless channel based on the received CSI-RS, obtains downlink channel state information (CSI), and feeds the CSI back to the network equipment.

[0004] The network device will allocate available time-frequency resources to the CSI-RS based on the number of CSI-RS ports and send the CSI-RS to the terminal device on this time-frequency resource. Correspondingly, the terminal device will also receive the CSI-RS on this time-frequency resource and feedback the CSI to the network device. Since the time-frequency resources occupied by the CSI-RS are related to the number of CSI-RS ports, as the number of CSI-RS ports supported by the protocol increases, the time-frequency resources occupied by the CSI-RS will increase accordingly.

[0005] Summary of the Invention

[0006] The present invention provides a method and a communication device for transmitting channel state information (CSI), which can reduce the time-frequency resources occupied by CSI-RS. The present invention provides the following technical solutions:

[0007] In a first aspect, a method for sending channel state information (CSI) is provided. The method can be executed by a terminal device, or by a module (such as a processor, chip, or chip system) applied to the terminal device, or by a logical node, logical module, or software that can implement all or part of the terminal device functions. The method includes: receiving a first reference signal, wherein the first frequency domain density of the resources of the first reference signal is less than the second frequency domain density of the resources of the second reference signal; sending target channel state information (CSI), wherein the target CSI includes the first CSI and / or the second CSI, wherein the first CSI is the CSI determined based on the first reference signal and the second CSI, or the first CSI is the CSI determined based on the second reference signal and the second CSI, and the second CSI is the CSI corresponding to the second reference signal.

[0008] In the above method, compared with the prior art in which the terminal device receives the first reference signal through resources with a higher frequency domain density, the terminal device in the present application receives the first reference signal through resources with a smaller frequency domain density (for example, resources of the first reference signal), which can reduce the overhead of the time-frequency resources occupied by the reference signal (for example, CSI-RS).

[0009] In an optional implementation, the method further includes: receiving third indication information from the network device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0010] Compared with the network device pre-setting the first frequency domain density, in the present application, the network device dynamically instructs the terminal side to feed back the first frequency domain density through the third indication information, which can improve the flexibility of the frequency domain density configuration.

[0011] In an optional implementation, before receiving the third indication information from the network device, the method further includes: sending first indication information to the network device, where the first indication information indicates the first frequency domain density.

[0012] Before receiving the third indication information sent by the network device, the terminal device feeds back the appropriate first frequency domain density to the network device to assist the network device in determining the first frequency domain density to avoid wasting time-frequency resources.

[0013] In an optional implementation, the method further includes: sending second indication information to the network device, where the second indication information indicates the first frequency domain density.

[0014] The terminal device estimates the channel state of the downlink channel based on the measurement results of the downlink channel, and can more accurately determine the first frequency domain density under the channel state of the current downlink channel. The network device configures the first reference signal resources with a reasonable frequency domain density based on the first frequency domain density fed back by the terminal side, thereby avoiding waste of time-frequency resources.

[0015] In an optional implementation, the method further includes: when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, receiving the second reference signal according to the resource of the second reference signal, the second CSI is measured based on the second reference signal, and the first CSI is measured based on the second reference signal.

[0016] In this embodiment, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the terminal device can provide the network device with more accurate CSI based on the resource feedback CSI (for example, the first CSI and the second CSI) of the second reference signal with a larger frequency domain density, thereby helping to improve the accuracy of the network device in determining the PMI.

[0017] In a possible implementation, the period of the first reference signal is a first period, the period of the second reference signal is a second period, and the first period is smaller than the second period.

[0018] The terminal device of the present application feeds back CSI to the network device based on the resource information of reference signals with different period durations configured by the network device; while ensuring the accuracy of the PMI indicated by the precoding matrix, the overhead of the time-frequency resources occupied by the reference signal (for example, CSI-RS) can be reduced.

[0019] In one possible implementation, the configuration information of the resources of the first reference signal also includes the number of reference signal ports, the first multiplexing type, and the first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, the second multiplexing type, and the second time-frequency domain position.

[0020] In one possible implementation, the first CSI includes a linear combination coefficient corresponding to at least one of a spatial domain vector, a frequency domain vector, or a space-frequency joint vector; the second CSI includes at least one of spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information.

[0021] In a possible implementation, the first reference signal is a first channel state information reference signal CSI-RS, and the second reference signal is a second CSI-RS.

[0022] In the second aspect, a method for receiving channel state information CSI is provided, which can be executed by a network device (i.e., a network device to which a serving cell belongs), or by a module applied to the network device (such as a processor, chip, or chip system, etc.), or by a logical node, logical module, or software that can implement all or part of the network device functions. The method includes: sending a first reference signal, the first frequency domain density of the resources of the first reference signal is less than the first frequency domain density of the resources of the second reference signal; receiving target channel state information CSI, the target CSI includes the first CSI and / or the second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or the first CSI is CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal.

[0023] In the above method, compared with the prior art in which the network device uses resources with higher frequency domain density to send the first reference signal to the terminal device, the network device in the present application sends the first reference signal to the terminal device through resources with smaller frequency domain density, which can reduce the overhead of the time-frequency resources occupied by the reference signal (for example, CSI-RS).

[0024] In an optional implementation manner, the method further includes: configuring resources of the first reference signal and resources of the second reference signal in the first resource set.

[0025] The network device can select an appropriate configuration mode of reference signal resources according to the actual distribution of time-frequency domain resources, which can improve the flexibility of reference signal resource configuration.

[0026] In an optional implementation, the method further includes: configuring resources for the first reference signal in a second resource set; and configuring resources for the second reference signal in a third resource set, where the second resource set and the third resource set are different.

[0027] The network device can configure the resources of the two reference signals in different resource sets according to the actual distribution of time-frequency domain resources, thereby improving the flexibility of the resource configuration of the reference signal.

[0028] In an optional implementation manner, the method further includes: sending third indication information to the terminal device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0029] Compared with the network device pre-setting the first frequency domain density, in the present application, the network device dynamically instructs the terminal side to feed back the first frequency domain density through the third indication information, which can improve the flexibility of the frequency domain density configuration.

[0030] In an optional implementation, before sending the third indication information to the terminal device, the method further includes: receiving first indication information from the terminal device, where the first indication information indicates a first frequency domain density.

[0031] Before the network device sends the third indication information to the terminal device, it receives the first frequency domain density sent by the terminal device, and configures the resources of the first reference signal according to the first frequency domain density determined by the terminal side to avoid wasting time-frequency resources.

[0032] In an optional implementation, the method further includes: receiving second indication information from the terminal device, where the second indication information indicates the first frequency domain density.

[0033] Since the terminal device estimates the channel state of the downlink channel based on the measurement results of the downlink channel, it can more accurately determine the first frequency domain density under the channel state of the current downlink channel. The network device configures the resources of the first reference signal with a reasonable frequency domain density based on the first frequency domain density fed back by the terminal side, thereby avoiding waste of time-frequency resources.

[0034] In an optional implementation, the method further includes: when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, sending the second reference signal according to the resource of the second reference signal, the second CSI is measured based on the second reference signal, and the first CSI is measured based on the second reference signal.

[0035] In this embodiment, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the terminal device can provide the network device with more accurate CSI based on the resource feedback CSI (for example, the first CSI and the second CSI) of the second reference signal with a larger frequency domain density, thereby helping to improve the accuracy of the network device in determining the PMI.

[0036] In an optional implementation, the period of the first reference signal is a first period, the period of the second reference signal is a second period, and the first period is smaller than the second period.

[0037] The network equipment configures the resources of reference signals with different periodic durations based on the two-level feedback CSI of the terminal equipment, so that the terminal equipment can feedback different CSIs according to the resources of reference signals with different periodic durations; while ensuring the accuracy of the PMI indicated by the precoding matrix, this can not only improve the flexibility of the resource configuration of the reference signal, but also reduce the overhead of the time-frequency resources occupied by the reference signal (for example, CSI-RS).

[0038] In an optional implementation, the configuration information of the resources of the first reference signal also includes the number of reference signal ports, the first multiplexing type and the first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, the second multiplexing type and the second time-frequency domain position.

[0039] In an optional implementation, the first CSI includes a linear combination coefficient corresponding to at least one of a spatial domain vector, a frequency domain vector, or a space-frequency joint vector; the second CSI includes at least one of spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information.

[0040] In an optional implementation, the first reference signal is a first channel state information reference signal CSI-RS, and the second reference signal is a second CSI-RS.

[0041] In a third aspect, a communication device is provided, which may be a terminal device, a module (such as a processor, a chip, or a chip system, etc.) used in a terminal device, or a logical node, a logical module or software that can implement all or part of the terminal functions. The beneficial effects of this section can be found in the description of the first aspect and will not be repeated here. The communication device has the function of implementing the behavior in the method example of the first aspect above. The function can be implemented by hardware, or it can be implemented by hardware executing the corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0042] In one possible implementation, the communication device includes: a transceiver module, wherein the transceiver module is used to receive a first reference signal, wherein the first frequency domain density of the resources of the first reference signal is less than the second frequency domain density of the resources of the second reference signal; and is further used to send target channel state information CSI, wherein the target CSI includes a first CSI and / or a second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal. The transceiver module can perform the corresponding functions in the above-mentioned method example of the first aspect. For details, please refer to the detailed description in the method example, which is not repeated here.

[0043] In a possible implementation, the transceiver module is further configured to receive third indication information from the network device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0044] In an optional implementation, before the transceiver module is used to receive the third indication information from the network device, it is also used to send first indication information to the network device, where the first indication information indicates the first frequency domain density.

[0045] In an optional implementation, the transceiver module is further configured to send second indication information to the network device, where the second indication information indicates the first frequency domain density.

[0046] In an optional implementation, the transceiver module is further configured to receive the second reference signal according to the resource of the second reference signal when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the second CSI being measured based on the second reference signal, and the first CSI being measured based on the second reference signal.

[0047] In an optional implementation, the period of the first reference signal is a first period, the period of the second reference signal is a second period, and the first period is smaller than the second period.

[0048] In an optional implementation, the configuration information of the resources of the first reference signal also includes the number of reference signal ports, the first multiplexing type and the first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, the second multiplexing type and the second time-frequency domain position.

[0049] In an optional implementation, the first CSI includes a linear combination coefficient corresponding to at least one of a spatial domain vector, a frequency domain vector, or a space-frequency joint vector; the second CSI includes at least one of spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information.

[0050] In an optional implementation, the first reference signal is a first channel state information reference signal CSI-RS, and the second reference signal is a second CSI-RS.

[0051] In a fourth aspect, a communication device is provided, which may be a network device (e.g., a base station), or may be executed by a module (e.g., a processor, a chip, or a chip system) applied to a network device, or may be a logical node, a logical module, or software that can implement all or part of the functions of the network device. The beneficial effects of this section can be found in the description of the second aspect and will not be repeated here. The communication device has the function of implementing the behavior in the method example of the second aspect above. The function can be implemented by hardware, or it can be implemented by hardware executing the corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0052] In one possible implementation, the communication device includes: a transceiver module and a processing module, wherein the transceiver module is used to send a first reference signal, the first frequency domain density of the resource of the first reference signal is less than the first frequency domain density of the resource of the second reference signal, and is also used to receive target channel state information CSI, the target CSI includes a first CSI and / or a second CSI, wherein the first CSI is a CSI determined based on the first reference signal and the second CSI, or a CSI determined based on the second reference signal and the second CSI, and the second CSI is the CSI corresponding to the second reference signal. The above-mentioned transceiver module and processing module can perform the corresponding functions in the above-mentioned second aspect method example. Please refer to the detailed description in the method example for details, which will not be repeated here.

[0053] In an optional implementation manner, the processing module is configured to configure resources of the first reference signal and resources of the second reference signal in a first resource set.

[0054] In an optional implementation, the processing module is further configured to configure resources of the first reference signal in a second resource set; and configure resources of the second reference signal in a third resource set, where the second resource set is different from the third resource set.

[0055] In an optional implementation, the transceiver module is further used to send third indication information to the terminal device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0056] In an optional implementation, before the transceiver module sends the third indication information to the terminal device, it is also used to receive first indication information from the terminal device, where the first indication information indicates the first frequency domain density.

[0057] In an optional implementation, the transceiver module is further used to receive second indication information from the terminal device, where the second indication information indicates the first frequency domain density.

[0058] In an optional implementation, the transceiver module is further configured to send a second reference signal according to the resource of the second reference signal when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the second CSI being measured based on the second reference signal, and the first CSI being measured based on the second reference signal.

[0059] In an optional implementation, the transceiver module is further configured to send the second reference signal, the period of the first reference signal is a first period, the period of the second reference signal is a second period, and the first period is smaller than the second period.

[0060] In an optional implementation, the configuration information of the resources of the first reference signal also includes the number of reference signal ports, the first multiplexing type and the first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, the second multiplexing type and the second time-frequency domain position.

[0061] In an optional implementation, the first CSI includes a linear combination coefficient corresponding to at least one of a spatial domain vector, a frequency domain vector, or a space-frequency joint vector; the second CSI includes at least one of spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information.

[0062] In an optional implementation, the first reference signal is a first channel state information reference signal CSI-RS, and the second reference signal is a second CSI-RS.

[0063] In a fifth aspect, a communication device is provided, which may be a terminal device, a module (such as a processor, chip, or chip system) used in a terminal device, or a logical node, logic module, or software that can implement all or part of the terminal functions. The communication device includes a processor and, optionally, a memory. The memory is used to store computer programs or instructions, and the processor is used to execute the computer programs or instructions in the memory; when the processor executes the computer program or instructions stored in the memory, the communication device executes the method performed by the terminal device in the above method embodiment.

[0064] In a sixth aspect, a communication device is provided. The communication device can be a network device (e.g., a base station), or it can be executed by a module (e.g., a processor, a chip, or a chip system) applied to a network device, or it can be a logical node, a logical module, or software that can implement all or part of the network device functions. The communication device includes a processor and, optionally, a memory. The memory is used to store computer programs or instructions, and the processor is used to execute the computer programs or instructions in the memory; when the processor executes the computer program or instructions stored in the memory, the communication device executes the method performed by the network device in the above method embodiment.

[0065] In a seventh aspect, a computer program product is provided, which includes: computer program code, which, when run, enables the method performed by the terminal device in the above aspects to be executed.

[0066] In an eighth aspect, a computer program product is provided, the computer program product comprising: a computer program code, which, when executed, enables the method performed by the network device in the above aspects to be executed.

[0067] In a ninth aspect, the present application provides a chip system comprising a processor for implementing the network device functions described in the aforementioned methods. In one possible design, the chip system further comprises a memory for storing program instructions and / or data. The chip system may be comprised solely of a chip or may include a chip and other discrete components.

[0068] In a tenth aspect, the present application provides a chip system comprising a processor for implementing the functions of the terminal device in the methods of the above aspects. In one possible design, the chip system further comprises a memory for storing program instructions and / or data. The chip system may be composed of a chip alone or may include a chip and other discrete components.

[0069] In an eleventh aspect, the present application provides a computer-readable storage medium, which includes a computer program or instructions. When the computer program or instructions are executed, the method performed by the network device in the above aspects is implemented.

[0070] In a twelfth aspect, the present application provides a computer-readable storage medium, which includes a computer program or instructions. When the computer program or instructions are executed, the method performed by the terminal device in the above aspects is implemented.

[0071] In the thirteenth aspect, an embodiment of the present application provides a communication system, including: the communication device of the third aspect mentioned above and the communication device of the fourth aspect mentioned above.

[0072] In the fourteenth aspect, an embodiment of the present application provides a communication system, including: the communication device of the fifth aspect mentioned above and the communication device of the sixth aspect mentioned above.

[0073] Any of the devices, computer storage media, computer program products, chips, or communication systems provided above are used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding schemes in the corresponding methods provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] FIG1 is a schematic diagram of a possible, non-limiting communication system provided in an embodiment of the present application;

[0075] FIG2 is a schematic diagram of a network structure of a communication system provided in an embodiment of the present application;

[0076] FIG3 is a schematic diagram of the structure of a terminal device and a network device provided in an embodiment of the present application;

[0077] FIG4 is a schematic diagram of a time-frequency domain resource location distribution according to an embodiment of the present application;

[0078] FIG5 is a schematic diagram of basic process steps for performing CSI measurement by a network device and a terminal device according to an embodiment of the present application;

[0079] FIG6 is an interactive diagram of a method for sending channel state information CSI provided in an embodiment of the present application;

[0080] FIG7 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0081] FIG8 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

[0082] FIG9 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0084] In the description of the present application, "at least one of the following items" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, a and b and c, wherein a, b, c can be single or multiple. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit quantity and execution order, and words such as "first" and "second" do not limit necessarily different.

[0085] It should be understood that, in this application, “in case of”, “if”, “when”, “if” and similar expressions can be used interchangeably.

[0086] It should be noted that, in this application, words such as "exemplarily" or "for example" are used to indicate giving an example, illustration, or explanation. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being a preferred implementation over other embodiments or designs. The use of words such as "exemplarily" or "for example" in this application is intended to present the relevant concepts in a concrete manner.

[0087] The technical solutions of the embodiments of the present application can be applied to various communication systems, including long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunication systems (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, fifth generation (5G) mobile communication systems or new radio access technologies (NR). The technical solutions provided in the present application can also be applied to future communication systems, such as sixth generation (6G) mobile communication systems.

[0088] In addition, the technical solutions provided in the embodiments of the present application can be applied to cellular links, public land mobile networks (PLMN), machine to machine (M2M) networks, Internet of Things (IoT) networks or other networks. It can also be applied to links between devices, such as device to device (D2D) links. D2D links can also be called sidelinks, where sidelinks can also be called side links or side links, etc. In the embodiments of the present application, the above terms all refer to links established between devices of the same type, and their meanings are the same. The so-called devices of the same type can be links between terminal devices, links between base stations, links between relay nodes, etc., and the embodiments of the present application do not limit this. For links between devices, there are D2D links defined in Release (Rel) 12 / 13 of the Third Generation Partnership Project (3GPP), as well as V2X links for vehicle-to-vehicle, vehicle-to-mobile, or vehicle-to-any-entity connections defined by 3GPP for connected vehicles, including Rel-14 / 15. These also include V2X links based on the New Radio (NR) system, currently under research by 3GPP in Rel-16 and subsequent releases.

[0089] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person skilled in the art will appreciate that, with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems.

[0090] Figure 1 shows a possible, non-limiting schematic diagram of a communication system. As shown in Figure 1, the communication system 100 includes at least one network device (such as 110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal device (such as 120a-120g in Figure 1, collectively referred to as 120). Among them, a network device is an entity on the network side for transmitting or receiving signals, such as the network device 110 can also be called a radio access network (RAN) node or a radio access network device, which is used to help terminal devices achieve wireless access; the network device 110 can be a base station, and the base station can broadly cover various names as follows, or be replaced with the following names, such as: node B (NodeB), evolved NodeB (eNB), next generation NodeB (gNB), next generation evolved NodeB (ng-eNB), relay station, access point, transmission point (TRP), transmitting point (TP), master eNodeB (MeNB), secondary eNodeB (SeNB), multi standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP) in wireless fidelity (WIFI) system, transmission node, transceiver node, baseband unit (base) Band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), etc. The base station can be a macro base station, a micro base station, a pico base station, a small station, a relay station, a balloon station, a relay node, a donor node or the like, or a combination thereof. The base station can also refer to a communication module, a modem or a chip for being set in the aforementioned device or apparatus. The base station can also be a network side device in a 6G network, a device that assumes the function of a base station in a future communication system, etc. The base station can support networks with the same or different access technologies. The base station can be fixed or mobile. For example, a helicopter or a drone can be configured to act as a mobile base station, and one or more cells can move according to the location of the mobile base station. In other examples, a helicopter or a drone can be configured to be used as a device for communicating with another base station. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network equipment.

[0091] In a network structure of a communication system, as shown in FIG2 , the network device 110 may be a wireless access device including a centralized unit (CU) node, a distributed unit (DU) node, or a CU node and a DU node. The wireless access device including the CU node and the DU node splits the protocol layer of the gNB in ​​the NR system, places some of the protocol layer functions under centralized control by the CU, and distributes some or all of the remaining protocol layer functions in the DU, which is centrally controlled by the CU. For example, the CU is responsible for processing non-real-time protocols and services, and implements the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implements the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer.

[0092] Optionally, as shown in Figure 2, the CU can be divided into a central unit-control plane (CU-CP) and a central unit-user plane (CU-UP). The CU-CP is responsible for control plane functions, primarily including radio resource control (RRC) and the control plane's corresponding packet data convergence protocol (PDCP-C). PDCP-C is responsible for control plane data encryption, integrity protection, and data transmission. The CU-UP is responsible for user plane functions, primarily including the service data adaptation protocol (SDAP) and the user plane's corresponding PDCP (PDCP-U). SDAP is responsible for processing core network data and mapping flows to bearers. PDCP-U is responsible for data plane encryption, integrity protection, header compression, sequence number maintenance, and data transmission. The CU-CP and CU-UP are connected via the E1 interface. The CU-CP represents the gNB's connection to the core network via the NG interface. The control plane connects to the DU via the F1 interface, namely F1-C. The CU-UP is connected to the DU via the F1 interface user plane, namely F1-U. Alternatively, the PDCP-C is also located in the CU-UP.

[0093] In an optional embodiment, the communication system 100 shown in Figure 1 may further include: a core network device (not shown in Figure 1). The core network device refers to a device in the core network (CN) that provides service support for the terminal device 120. For example, the core network device may be: an access and mobility management function (AMF) entity, a session management function (SMF) entity, a user plane function (UPF) entity, etc., which are not listed here one by one. Among them, the AMF entity can be responsible for access management and mobility management of the terminal device 120; the SMF entity can be responsible for session management, such as user session establishment; the UPF entity can be a functional entity of the user plane, mainly responsible for connecting to the external network. It should be noted that in this application, the entity may also be referred to as a network element or a functional entity. For example, the AMF entity may also be referred to as an AMF network element or an AMF functional entity. For another example, the SMF entity may also be referred to as an SMF network element or an SMF functional entity.

[0094] The terminal device 120 is a wireless terminal device capable of receiving network device scheduling and indication information, wherein the wireless terminal device may be a device that provides voice and / or data connectivity to a user, or a handheld device with wireless connection function, or other processing device connected to a wireless modem; the wireless terminal device may communicate with one or more core networks or the Internet via a wireless access network (such as a radio access network, RAN). The terminal device 120 may be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it may also be deployed on water (such as a ship, etc.); it may also be deployed in the air (such as an airplane, balloon, and satellite, etc.). The embodiments of the present application do not limit the scenario in which the terminal device is located.

[0095] In this application, the terminal device 120 may also be referred to as a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), etc. The terminal device in the embodiment of the present application may be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a wireless modem (modem), a handheld device (handset), a laptop computer (laptop computer), a machine type communication (MTC) terminal, and may also be a wireless terminal used in scenarios such as virtual reality (VR), augmented reality (AR), industrial control (industrial control), self-driving, remote medical, smart grid, transportation safety, smart city, and smart home. In this application, the aforementioned terminal devices and chips applicable to the aforementioned terminal devices are collectively referred to as terminal devices. It should be understood that the embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0096] As an example, communication between a network device (e.g., 110a) and a terminal device (e.g., 120a) in the communication system 100 shown in FIG1 can be performed in the form shown in FIG3. As shown in FIG3, the terminal device includes a processor 101, a memory 102, and a transceiver 103. The transceiver 103 includes a transmitter 1031, a receiver 1032, and an antenna 1033. The network device includes a processor 201, a memory 202, and a transceiver 203. The transceiver 203 includes a transmitter 2031, a receiver 2032, and an antenna 2033. The receiver 1032 can be configured to receive transmission control information via the antenna 1033, and the transmitter 1031 can be configured to send transmission feedback information to the network device via the antenna 1033. The transmitter 2031 can be configured to send transmission control information to the terminal device via the antenna 2033, and the receiver 2032 can be configured to receive transmission feedback information sent by the terminal device via the antenna 2033.

[0097] In the embodiments of the present application, when a network device sends data to a terminal device, it is necessary to determine parameters such as a precoding matrix based on the channel state information (CSI) fed back by the terminal device. To facilitate understanding of the embodiments below, the following briefly describes the relevant terms involved in this application.

[0098] (1) Channel State Information (CSI)

[0099] Channel state information (CSI) is used to indicate the channel properties of a communication link. The CSI includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI).

[0100] (2) CSI report

[0101] In a wireless communication system, information describing the channel properties of a communication link is reported by a receiving end (e.g., a terminal device) to a transmitting end (e.g., a network device). The CSI report may include, but is not limited to, one or more of the following: a precoding matrix indicator (PMI), a rank indicator (RI), a channel quality indicator (CQI), a channel state information reference signal resource indicator (CRI), and a layer indicator (LI). The embodiments of the present application do not limit the specific content of the CSI report.

[0102] (3) Channel State Information Reference Signal (CSI-RS)

[0103] In a 5G NR system, to ensure the communication quality of the downlink channel between a network device (e.g., a base station) and a terminal device (e.g., a UE), the network device typically instructs the terminal device to detect the downlink wireless channel. For example, the network device sends a CSI-RS to the terminal device. The terminal device measures and evaluates the downlink wireless channel based on the received CSI-RS and feeds back the measurement results (e.g., CSI) to the network device. The network device can set appropriate transmission parameters for downlink data transmission based on the measurement results fed back by the terminal device.

[0104] (4) Precoding matrix indicator (PMI)

[0105] The PMI may be used to indicate a precoding matrix available to a network device; the network device may restore the precoding matrix based on the PMI.

[0106] It should be noted that the precoding matrix can be a precoding matrix determined by the terminal device based on the channel matrix of each frequency domain unit; wherein the frequency domain unit, that is, the unit of frequency domain resources, can represent different frequency domain resource granularities. Frequency domain units may include but are not limited to subbands, resource blocks (RBs), subcarriers, resource block groups (RBGs) or precoding resource block groups (PRGs). In addition, the frequency domain length of a frequency domain unit can be R times the subband or frequency domain subband, R<=1, for example, the value of R can be 1 or 1 / 2, or a resource block RB. The precoding matrix can be determined by the terminal device through channel estimation or other methods or based on the reciprocity of the channel. However, it should be understood that the specific method for the terminal device to determine the precoding matrix is ​​not limited to the above. The specific implementation method can refer to the existing technology and will not be repeated here.

[0107] For example, the precoding matrix can be obtained by performing singular value decomposition (SVD) on the channel matrix or the covariance matrix of the channel matrix, or by performing eigenvalue decomposition (EVD) on the covariance matrix of the channel matrix. It should be understood that the determination methods of the precoding matrix listed above are only examples and should not constitute any limitation to this application. The determination method of the precoding matrix can refer to the existing technology and will not be repeated here.

[0108] (5) Basic structure of CSI-RS

[0109] In existing protocols, CSI-RS can support up to 32 different antenna ports, each of which is a channel to be detected. The time-frequency domain resource mapping of CSI-RS is shown in Table 1.

[0110] Table 1 CSI-RS time-frequency domain resource mapping

[0111] In Table 1, "Ports" indicates the number of configured CSI-RS ports, and "Density" indicates the frequency domain density of the configured CSI-RS. "cdm-Type" indicates the multiplexing type of each code division multiplexing (CDM); X in CDM X indicates the number of CSI-RS ports multiplexed in a CDM group, and "no CDM" indicates no port multiplexing, that is, there is only one port on one resource element (RE). Code, OCC) sequence is shown in Table 2; "fd-CDM2" means that 2 ports are multiplexed on 2 frequency domain REs, and the port orthogonality is achieved through the frequency domain OCC with a length of 2. The specific OCC sequence is shown in Table 3; "cdm4-FD2-TD2" means that 4 ports are multiplexed on 2 frequency domain REs and 2 time domain symbols, a total of 4 REs, and the port orthogonality is achieved through the frequency domain OCC with a length of 2 and the time domain OCC with a length of 2. The specific OCC sequence is shown in Table 4; "cdm8-FD2-TD4" means that 8 ports are multiplexed on 2 frequency domain REs and 4 time domain symbols, a total of 8 REs, and the port orthogonality is achieved through the frequency domain OCC with a length of 2 and the time domain OCC with a length of 4. The specific OCC sequence is shown in Table 5. It should be noted that in Tables 2 to 5, w f (·) represents the frequency domain orthogonal cover code, w t (·) represents a time-domain orthogonal cover code.

[0112] Table 1 Indicates the time-frequency resource position of the CDM group in an RB. represents the frequency domain position, Indicates the time domain position. "CDM group index j" indicates the CDM group index. Taking row 16 as an example, with 32 ports (32ports), "fd-CDM2" indicates that each CDM group multiplexes 2 ports, so there are a total of 16 CDM groups, and the CDM group indexes are 0 to 15. k' and l' indicate the frequency domain and time domain indexes of the REs occupied in one CDM group. Taking row 16 as an example, one CDM group "fd-CDM2" occupies a total of 2 REs, and they are 2 frequency domain REs, so k' corresponds to 0, 1, and l' corresponds to 0. Indicates the starting frequency domain position and starting time domain position of each CDM group's REs. Combined with k' and l', it indicates the frequency domain position and time domain position of all REs in each CDM group. Figure 4 shows the time and frequency domain resource positions in different rows of Table 1. Taking the 32ports in Figure 4 as an example, it includes three multiplexing types: "fd-CDM2," "cdm4-FD2-TD2," and "cdm8-FD2-TD4." For "fd-CDM2," there are four independently configured frequency domain positions k0, k1, k2, and k3, and four time domain positions l0, l0+1, l1, and l1+1, which together form 16 CDM groups. l0 and l1 are configurable, while the remaining two time domain positions can default to l0+1 and l1+1. For "cdm4-FD2-TD2," there are four independently configured frequency domain positions k0, k1, k2, and k3, and two time domain positions l0 and l1, which together form 8 CDM groups. For "cdm8-FD2-TD4", there are 4 independently configured frequency domain positions k0, k1, k2, k3 and 1 time domain position l0, which together constitute 4 CDM groups.

[0113] Table 2

[0114] Table 3

[0115] Table 4

[0116] Table 5

[0117] In addition, the network device may create an index ranking of the CSI-RS ports according to the following formula: p = 3000 + s + jL; j = 0, 1, ..., N / L-1 s = 0, 1, ..., L-1;

[0118] Where p represents the CSI-RS port index, j represents the index of the code division multiplexing (CDM) group, s represents the index of the orthogonal cover code (OCC) sequence within a CDM group, N represents the total number of ports, and L represents the size of a CDM group.

[0119] 5) Spatial domain vector, also known as beam vector, spatial beam basis vector, spatial basis vector, or spatial basis. Each element in the spatial domain vector represents the weight of each antenna port. Based on the weights of each antenna port represented by each element in the spatial domain vector, the signals from each antenna port are linearly superimposed to form an area with a strong signal in a certain direction in space.

[0120] The length of the spatial vector may be the number of transmit antenna ports in a polarization direction, Ns, where Ns ≥ 1 and is an integer. The spatial vector may be, for example, a column vector or a row vector of length Ns. This application does not limit this.

[0121] Optionally, the spatial domain vector is taken from a DFT matrix. Each column vector in the DFT matrix can be referred to as a DFT vector. In other words, the spatial domain vector can be a DFT vector. The spatial domain vector can be, for example, a DFT vector defined in a type II codebook in NR protocol TS 38.214 version 15 (release 15, R15).

[0122] 6) The spatial vector set may include spatial vectors of various lengths to correspond to different numbers of antenna ports. In this embodiment of the present application, the length of the spatial vector is Ns, so the length of each spatial vector in the spatial vector set to which the spatial vector reported by the terminal device belongs is Ns.

[0123] In one possible design, the spatial vector set may include Ns spatial vectors, each of which may be orthogonal to each other. Each spatial vector in the spatial vector set may be derived from a two-dimensional (2D) discrete Fourier transform (DFT) matrix. 2D may represent two different directions, such as horizontal and vertical. If the number of antenna ports in the horizontal and vertical directions is M1 and M2, respectively, then Ns = M1M2.

[0124] 7) Frequency domain vectors (also called frequency domain bases) are vectors that represent the frequency domain channel's variation patterns. Each frequency domain vector can represent a specific variation pattern. As a signal travels through a wireless channel, it can take multiple paths from the transmitting antenna to the receiving antenna. Multipath delay causes frequency-selective fading, which is a variation of the frequency domain channel. Therefore, different frequency domain vectors can be used to represent the frequency domain channel variation patterns caused by delays along different transmission paths.

[0125] The length of the frequency domain vector can be determined by the number of frequency domain units to be reported pre-configured in the reporting bandwidth, or by the length of the reporting bandwidth, or by a protocol predefined value. This application does not limit the length of the frequency domain vector. The reporting bandwidth may, for example, refer to the CSI reporting bandwidth (CSI-ReportingBand) carried in the CSI reporting pre-configuration in the higher-layer signaling (such as the radio resource control (RRC) message).

[0126] The length of the frequency domain vector uf can be denoted as Nsb, where Nsb is a positive integer. The frequency domain vector can be, for example, a column vector or a row vector of length Nsb. This application does not limit this.

[0127] 8) The frequency domain vector set may include frequency domain vectors of various lengths. In the embodiment of the present application, the length of the frequency domain vector is Nsb, so the length of each frequency domain vector in the frequency domain vector set to which the frequency domain vector reported by the terminal device belongs is Nsb.

[0128] In one possible design, the frequency domain vector set may include Nsb frequency domain vectors. The Nsb frequency domain vectors may be mutually orthogonal. Each frequency domain vector in the frequency domain vector set may be taken from a DFT matrix or an IDFT matrix (i.e., a conjugate transposed matrix of a DFT matrix).

[0129] (6) Antenna port

[0130] An antenna port, or simply a port, can be understood as a transmitting antenna identified by a receiving device, or a spatially distinguishable transmitting antenna. An antenna port can be preconfigured for each virtual antenna. Each virtual antenna can be a weighted combination of multiple physical antennas. Each antenna port can correspond to a reference signal and, therefore, can be referred to as a reference signal port, such as a channel state information reference signal (CSI-RS) port or a sounding reference signal (SRS) port.

[0131] (7) Dual-domain compression can include compression in two dimensions: spatial domain compression and frequency domain compression. Spatial domain compression can specifically refer to selecting one or more spatial domain vectors from a set of spatial domain vectors as vectors for constructing a precoding vector. Frequency domain compression can refer to selecting one or more frequency domain vectors from a set of frequency domain vectors as vectors for constructing a precoding vector. Among them, a matrix constructed by a spatial domain vector and a frequency domain vector can be called a space-frequency component matrix, for example. The selected one or more spatial domain vectors and one or more frequency domain vectors can construct one or more space-frequency component matrices. The weighted sum of the one or more space-frequency component matrices can be used to construct a space-frequency precoding matrix corresponding to a spatial layer. In other words, the space-frequency precoding matrix can be approximated as the weighted sum of the space-frequency component matrices constructed by the above-mentioned selected one or more spatial domain vectors and one or more frequency domain vectors. Based on the space-frequency precoding matrix corresponding to a spatial layer, the precoding vector corresponding to each frequency domain unit on the spatial layer can be determined.

[0132] (8) Joint space-frequency domain compression refers to representing the channel represented by the space-frequency domain matrix (space-domain vector matrix and frequency-domain vector matrix) using a space-frequency domain vector (e.g., a space-frequency domain column vector or a space-frequency domain row vector). In other words, the space-frequency domain vector can indicate the channel in the joint space-frequency domain. For example, if the terminal device uses a single receiving antenna, the channel can be represented by a single space-frequency domain vector; if the terminal device uses multiple receiving antennas, the channel can be represented by multiple space-frequency domain vectors.

[0133] (9) The space-frequency joint vector, also known as the space-frequency joint basis, is a vector that can be used to represent the variation pattern of the channel in the joint space-frequency domain. If the channel is a single-polarized channel, then the dimension of the space-frequency joint vector matrix is ​​((M1M2)Nsb)L, where M1 is the number of antenna ports in the horizontal direction of the network device, M2 is the number of antenna ports in the vertical direction of the network device, Nsb is the number of frequency units, and L is the number of paths. It should be understood that if the channel is a dual-polarized channel, then the dimension of the space-frequency joint vector matrix is ​​(2(M1M2)Nsb)L.

[0134] (10) The space-frequency combining coefficient matrix, also known as the combining coefficient matrix, superposition coefficient matrix, or projection coefficient matrix, is used to represent the weight of a space-domain vector and a frequency-domain vector in weighted summation. The space-frequency combining coefficient includes amplitude and phase. As mentioned above, the space-frequency combining coefficient has a one-to-one correspondence with a vector pair consisting of a space-domain vector and a frequency-domain vector. In other words, each space-frequency combining coefficient corresponds to a space-domain vector and a frequency-domain vector.

[0135] (11) The space-frequency joint combining coefficient matrix, also known as the joint combining coefficient matrix, the joint superposition coefficient matrix, or the joint projection coefficient matrix, is used to represent the weights of one or more frequency domain bases and one or more spatial domain bases in the space-frequency joint basis matrix during weighted summation. A frequency domain basis may correspond to one or more spatial domain bases, and a spatial domain basis may correspond to one or more frequency domain bases.

[0136] (12) Basic process of measuring CSI between network equipment and terminal equipment

[0137] In traditional frequency division duplexing (FDD), the network device typically instructs the terminal device to perform channel measurement. In response, the terminal device feeds back the CSI (CSI) to the network device. Figure 5 illustrates the basic steps of a CSI measurement process between the network device and the terminal device.

[0138] Step 1: The network device sends channel measurement configuration information to the terminal device to instruct the terminal device to measure the time-frequency information and behavior (eg, codebook type) of the channel.

[0139] Step 2: The network device sends a CSI-RS, also known as a pilot signal, to the terminal device through a pre-configured channel measurement resource (CMR). The CSI-RS is used by the terminal device to perform channel measurement. The CSI-RS can be a non-zero power channel state information reference signal (NZP CSI-RS). For example, in NR, the terminal device sends an NZP CSI-RS through the network device to detect the channel state of the downlink channel.

[0140] Step 3: The terminal device receives CSI-RS (eg, NZP CSI-RS) according to the CMR pre-configured by the network device, and performs channel measurement based on the CSI-RS.

[0141] Optionally, for step 2 and step 3, the network device may further pre-configure a set of interference measurement resources (IMRs) corresponding to the CMRs for the terminal device; accordingly, the terminal device receives reference signals according to these pre-configured IMRs and performs interference measurement.

[0142] Step 4: The terminal device calculates the CSI based on the channel measurement results and the interference measurement results.

[0143] Step 5: The terminal device feeds back the CSI to the network device. CSI includes but is not limited to PMI, RI, and CQI.

[0144] Step 6: The network device receives and parses the CSI to obtain parameters such as PMI, RI, and CQI. The network device determines the precoding matrix for the data sent to the terminal device based on the PMI, the modulation and coding scheme (MCS) for the data sent to the terminal device based on the CQI, and the number of data streams sent to the terminal device based on the RI.

[0145] After introducing the professional terms related to this application, the method provided in the embodiments of this application is described in detail with reference to the accompanying drawings.

[0146] As can be seen from the background technology, the time-frequency resources occupied by CSI-RS are related to the number of CSI-RS ports; as the number of CSI-RS ports supported by the protocol increases, the time-frequency resources occupied by CSI-RS will increase accordingly. This application proposes a method for transmitting CSI-RS that can reduce the time-frequency resources occupied by CSI-RS.

[0147] (13) Introduction to Control Signaling

[0148] The interactive information sent between terminal devices and network devices can be transmitted through the control signaling of Layer 1, Layer 2, or Layer 3 on the network side in the 3rd Generation Partnership Project (3GPP):

[0149] For sending downlink information, network devices can use the following three methods:

[0150] Method a1: The network device sends downlink control information (e.g., CSI-RS) to the terminal device via Downlink Control Information (DCI) instructions at the physical layer. This downlink control information can be sent independently or only together with other downlink control information (e.g., radio resource scheduling information). It should be understood that the physical layer is also called Layer 1 or L1.

[0151] Method a2: The network device sends downlink control information to the terminal device via the Control Element (CE) of the Media Access Control (MAC) layer. This downlink control information can be sent independently or together with other downlink control information. The MAC layer is also known as Layer 2 or L2.

[0152] Method a3: The network device may also send downlink control information to the terminal device via RRC signaling at the RRC layer. Similarly, the downlink control information may be sent independently or together with other RRC signaling (e.g., RRC reconfiguration information, RRC reconfiguration completion information, etc.). It should be understood that the RRC layer is also called layer 3 or L3.

[0153] For sending uplink information, the terminal device can also use the following three methods to send:

[0154] Method b1: The terminal device sends uplink control information (UCI) to the network device through the physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) of layer 1; the uplink control information can be used by the terminal device to report the status information of the execution unit. The uplink control information can be sent independently or uploaded together with other uplink control information (for example, CSI).

[0155] Mode b2: The terminal device sends the UCI to the network device through the CE of layer 2; the UCI can be sent independently or together with other information.

[0156] Method b3: The terminal device can also send UCI to the network device through the RRC signaling of layer 3. The UCI can be sent independently or uploaded together with other RRC signaling (for example, RRC connection reconfiguration completion information).

[0157] Exemplarily, the network device sends the CSI-RS of the downlink channel to the terminal device through the RRC signaling of the layer 3 layer; after the terminal device receives the CSI-RS of the downlink channel, it performs channel state measurement on the downlink channel and sends the channel measurement result (e.g., CSI) to the network device through the RRC signaling of the layer 3 layer.

[0158] Exemplarily, the network device sends the CSI-RS to the terminal device through the CE of the layer 2 layer; after receiving the CSI-RS, the terminal device performs channel state measurement on the downlink channel and sends the channel measurement result of the downlink channel (e.g., CSI) to the network device through the CE of the layer 2 layer.

[0159] Before introducing a method for sending channel state information CSI proposed in this application, a brief description of the execution entities involved in this application is first given; in the interaction flow diagram of this application, network devices and terminal devices are used as examples of the execution entities of the interaction diagram to illustrate the method provided by this application, but this application does not limit the execution entities of the interaction diagram.

[0160] For example, the network device may also be a chip, chip system, or processor applied to the network device, or a logical node, logic module, or software that can realize all or part of the functions of the network device; the above-mentioned terminal device may also be a chip, chip system, or processor applied to the terminal, or a logical node, logic module, or software that can realize all or part of the terminal functions.

[0161] Exemplarily, the network device may be the base station 110a in FIG. 1 , and the terminal device may be the terminal device 120a in FIG. 1 .

[0162] The following embodiments are described by taking the execution subject of the method 600 for sending channel state information CSI as a terminal device as an example.

[0163] As shown in FIG6 , it is a schematic diagram of an interactive process of a method 600 for sending channel state information CSI provided in an embodiment of the present application. The method 600 includes steps 601 to 602 , which are described in detail below.

[0164] Step 601: The terminal device receives a first reference signal, and the first frequency domain density of the first reference signal resource is less than the second frequency domain density of the second reference signal resource. Accordingly, the network device sends the first reference signal.

[0165] Among them, the first reference signal can be the first channel state information reference signal CSI-RS, or it can be a demodulation reference signal (DMRS) or a time-frequency tracking reference signal (TRS); similarly, the second reference signal can be the first channel state information reference signal CSI-RS, or it can be a demodulation reference signal (DMRS) or a time-frequency tracking reference signal (TRS); this application does not limit this.

[0166] The first reference signal or the second reference signal may be a periodic or semi-persistent reference signal, or may be a non-periodic reference signal.

[0167] When the first reference signal or the second reference signal can be a periodic or semi-persistent reference signal, the network device can configure the first reference signal or the second reference signal with different periods, that is, configure the resources of the first reference signal or the second reference signal to resources with different period lengths.

[0168] For example, the network device may configure the resources of the first reference signal as resources with a shorter period (e.g., the first period), and configure the resources of the second reference signal as resources with a longer period (e.g., the second period). For example, the first period may be 4ms, 5ms, etc.; the second period may be 50ms, 100ms, etc.

[0169] Before step 601, the network device configures resources for the first reference signal and resources for the second reference signal, wherein the resources for the first reference signal are used by the network device to send the first reference signal to the terminal device, and the resources for the second reference signal are used by the network device to send the second reference signal to the terminal device.

[0170] In an optional implementation, the network device may configure the resources of the first reference signal and the resources of the second reference signal in one resource set, or may configure them separately in two resource sets.

[0171] For example, the network device configures resources for the first reference signal and resources for the second reference signal in the first resource set.

[0172] The configuration information of the resources of the first reference signal (or the resources of the second reference signal) may include but is not limited to frequency domain density (e.g., CSI-RS frequency domain density). For example, the configuration information of the resources of the first reference signal includes the first frequency domain density, and the configuration information of the resources of the second reference signal includes the second frequency domain density.

[0173] The frequency domain density can be calculated using the following formula: ρ = N1 / N2 / M

[0174] Wherein, ρ represents the frequency domain density, N1 represents the number of REs occupied by the reference signal port (e.g., CSI-RS port), N2 represents the number of reference signal ports (e.g., the number of CSI-RS ports), and M represents the number of physical resource blocks (PRBs) occupied by the reference signal port (e.g., CSI-RS port).

[0175] For example, taking the reference signal as CSI-RS, as shown in Figure 4, the number of REs occupied by 32 antenna ports N1 is 32, N2 indicates that the number of CSI-RS ports is 32, and the number of PRBs is 1. It can be seen from the frequency domain density formula that ρ = 1.

[0176] In a possible implementation, the configuration information of the first reference signal resource (or the second reference signal resource) may further include, but is not limited to, the number of reference signal ports, the multiplexing type, and the time-domain and frequency-domain positions.

[0177] As an example, the configuration information of the resources of the first reference signal may include the number of reference signal ports (for example, the number of CSI-RS ports), the first multiplexing type and the first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, the second multiplexing type and the second time-frequency domain position.

[0178] For example, taking the reference signal as CSI-RS, the number of CSI-RS ports can be 8, 16, 32, 64, 128 or 256, etc.; the first frequency domain density can be 0.25, 0.125, 0.0625, etc., and the second frequency domain density can be 1 or 0.5, etc., and you can refer to the relevant description in Table 1 above, which will not be repeated here; the first multiplexing type (or second multiplexing type) can include but is not limited to fd-CDM2, cdm4-FD2-TD2 and cdm4-FD2-TD2, and you can refer to the relevant description above, which will not be repeated here; the first time domain and frequency domain position (or the second time domain and frequency domain position) can refer to the calculation method of the time-frequency resource position in the time-frequency domain resource mapping method of CSI-RS in Table 1, which will not be repeated here.

[0179] It should also be noted that the first reference signal (or second reference signal) is used for downlink channel measurement; the first reference signal (or second reference signal) can be configured with 1, 2, 4, 8, 16, 24, or 32 antenna ports. Of course, with the development of NR technology, the first reference signal (or second reference signal) can also be configured with a higher number of antenna ports (for example, 64, 128, or 256, etc.).

[0180] When configuring reference signal resources, the network device may configure reference signal resources with two different frequency domain densities. For example, the network device configures the frequency domain density of the first reference signal resources to be the first frequency domain density, and configures the frequency domain density of the second reference signal resources to be the first frequency domain density, wherein the first frequency domain density is less than the second frequency domain density. The network device may indicate the first reference signal resources and the second reference signal resources to the terminal device via RRC signaling. Furthermore, the network device may send the first reference signal to the terminal device via the first reference signal resources, and send the second reference signal via the second reference signal resources. Accordingly, the terminal device receives the first reference signal via the first reference signal resources, and receives the second reference signal via the second reference signal resources.

[0181] Step 602: The terminal device sends target channel state information CSI, where the target CSI includes a first CSI and / or a second CSI, wherein the first CSI is a CSI determined based on the first reference signal and the second CSI, or the first CSI is a CSI determined based on the second reference signal and the second CSI, and the second CSI is the CSI corresponding to the second reference signal.

[0182] The first CSI (or second CSI) may refer to a measurement result of a downlink channel measured by a terminal device based on a first reference signal (or second reference signal), and is used to reflect channel state information of the downlink channel. The first CSI may be CSI determined based on the first reference signal and the second CSI, or may be CSI determined based on the second reference signal and the second CSI.

[0183] In one possible implementation, the first CSI includes a linear combination coefficient corresponding to at least one of a spatial domain vector, a frequency domain vector, or a space-frequency joint vector; the second CSI includes at least one of spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information.

[0184] The spatial vector indication information is used to indicate a spatial vector, and the network device can determine a specific spatial vector based on the spatial vector indication information. Similarly, the frequency vector indication information is used to indicate a spatial vector, and the network device can determine a specific spatial vector based on the frequency vector indication information. The joint space-frequency vector indication information is used to indicate a joint space-frequency vector, and the network device can determine a specific joint space-frequency vector based on the joint space-frequency vector indication information.

[0185] Optionally, the spatial domain vector, frequency domain vector, or space-frequency joint vector indicated by at least one of the spatial domain vector indication information, frequency domain vector indication information, or space-frequency joint vector indication information in the second CSI may be a characteristic subspace vector. The first CSI may further include a linear combination coefficient corresponding to at least one of the characteristic subspace vector corresponding to the spatial domain vector, the characteristic subspace vector corresponding to the frequency domain vector, or the characteristic subspace vector corresponding to the space-frequency joint vector; and the second CSI includes at least one of the characteristic subspace vector indication information corresponding to the spatial domain vector, the characteristic subspace basis vector indication information corresponding to the frequency domain vector, or the characteristic subspace vector indication information corresponding to the space-frequency joint vector.

[0186] It should be noted that the characteristic subspace vector indication information corresponding to the spatial domain vector (or frequency domain vector or spatial-frequency joint vector) can refer to the relevant description of the spatial domain vector (or frequency domain vector or spatial-frequency joint vector) indication information above, and will not be repeated here.

[0187] After the terminal device receives the first reference signal through the resources of the first reference signal, it will measure and evaluate the downlink channel and feedback the channel state information (for example, the first CSI) to the network device in the form of a CSI report. Similarly, after the terminal device receives the second reference signal through the resources of the second reference signal, it will also measure and evaluate the downlink channel and feedback the channel state information (for example, the second CSI) to the network device in the form of a CSI report; the network device can configure appropriate precoding for downlink data transmission based on the channel state information feedback from the terminal device.

[0188] For example, after receiving the first reference signal, the terminal device will measure the downlink channel and send the first CSI representing the channel properties to the network device. Similarly, after receiving the second reference signal, the terminal device will also measure the downlink channel and send the second CSI representing the channel properties to the network device, where the first CSI is CSI determined based on the second CSI and the measurement result of the downlink channel (for example, the measurement result obtained based on the first reference signal or the second reference signal).

[0189] In another possible implementation, the network device may configure the resources of the first reference signal and the resources of the second reference signal as periodic or semi-continuous resources, for example, configuring the resources of the first reference signal as resources with a shorter period, and configuring the resources of the second reference signal as resources with a longer period; when the time-frequency domain position indicated by the resources of the first reference signal coincides with the time-frequency domain position indicated by the resources of the second reference signal, the terminal device may determine the first CSI based on the second reference signal and feed the first CSI back to the network device. When the time-frequency domain position indicated by the resources of the first reference signal does not coincide with the time-frequency domain position indicated by the resources of the second reference signal, the terminal device may determine the first CSI based on the first reference signal and feed the first CSI back to the network device, and determine the second CSI based on the second reference signal and feed the second CSI back to the network device.

[0190] Since the time-frequency resources required for the terminal device to feed back the second CSI to the network device are relatively large, while the time-frequency resources required to feed back the first CSI are relatively small; therefore, in order to ensure the accuracy of the terminal device's feedback of the downlink channel properties, the terminal device can use the resources of the reference signal with a higher frequency domain density (for example, the resources of the second reference signal) to feed back the second CSI to the network device, and use the resources of the reference signal with a lower frequency domain density (for example, the resources of the first reference signal) to feed back the first CSI. In this way, the overhead of the time-frequency domain resources occupied by the reference signal can be reduced while ensuring the accuracy of the network device determining the downlink transmission parameters (for example, the precoding matrix) based on the first CSI and the second CSI.

[0191] In a possible implementation manner, the network device configures resources for the first reference signal and resources for the second reference signal in the first resource set.

[0192] The network device may configure resources for a first reference signal and resources for a second reference signal in the first resource set, wherein the resources for the first reference signal and the resources for the second reference signal are different.

[0193] For example, the first resource set includes at least two different resources. The network device can configure one resource among the at least two different resources as a resource for a first reference signal, and configure another resource among the at least two different resources as a resource for a second reference signal. The resource for the first reference signal and the resource for the second reference signal are different.

[0194] In this embodiment, the network device may select a suitable reference signal resource configuration method according to the actual distribution of time-frequency domain resources, so as to improve the flexibility of reference signal resource configuration.

[0195] In a possible implementation, the network device configures resources for a first reference signal in a second resource set; and configures resources for a second reference signal in a third resource set, where the second resource set and the third resource set are different.

[0196] Exemplarily, the second resource set includes at least one resource (e.g., a CSI-RS resource), and the third resource set includes at least one resource (e.g., a CSI-RS resource). The network device may configure a resource for a first reference signal in a resource in the second resource set, and configure a resource for a second reference signal in a resource in the third resource set, wherein the resource for the first reference signal and the resource for the second reference signal are different.

[0197] In this embodiment, the network device may configure two reference signal resources in different resource sets according to the actual distribution of time-frequency domain resources, thereby improving the flexibility of reference signal resource configuration.

[0198] In a possible implementation, the method 600 further includes: the period for the terminal device to receive the first reference signal is a first period, the period for the second reference signal is a second period, and the first period is smaller than the second period.

[0199] It should be noted that, under the premise of ensuring the PMI measurement accuracy, the terminal device can feedback the second CSI (for example, spatial vector indication information, frequency domain vector indication information or space-frequency joint vector indication information, etc.) in a long period, and feedback the first CSI (for example, linear combination coefficients corresponding to spatial vectors, frequency domain vectors or space-frequency joint vectors, etc.) in a short period; therefore, when the network device configures the resources of the reference signal, it can configure the resources of the reference signal into periodic or semi-continuous resources of two reference signals with different periods; accordingly, when the network device uses the resources of reference signals with different periods to send two reference signals (for example, CSI-RS) respectively, the corresponding periods of the two reference signals (for example, CSI-RS) are also different.

[0200] It should also be noted that the reference signal (e.g., CSI-RS) can be periodic or semi-persistent, where the semi-persistent reference signal needs to be triggered by control signaling (e.g., DCI or MAC-CE), while the periodic reference signal does not need to be triggered by control signaling.

[0201] As an example, the network device may configure the resources of the first reference signal to have a short period. Accordingly, the first reference signal is a reference signal with a short period. For example, the period of the resources of the first reference signal is the first period. Accordingly, the period of the first reference signal is the first period. Similarly, the network device may configure the resources of the second reference signal to have a long period. Accordingly, the second reference signal is a reference signal with a long period. For example, the period of the resources of the second reference signal is the second period. Accordingly, the period of the second reference signal is the second period. The duration of the first period is shorter than the duration of the second period. The duration of the first period can be 4ms, 5ms, etc.; the duration of the second period can be 50ms, 100ms, etc.

[0202] In this embodiment, the network device configures the resources of reference signals with different period durations based on the two-level feedback CSI of the terminal device, so that the terminal device can receive the reference signal according to the resources of the reference signals with different period durations; for example, the terminal device can feedback the first CSI of the channel (for example, the linear combination coefficient corresponding to the spatial domain vector, frequency domain vector, etc. of the channel) based on a short period (for example, the first period), and feedback the second CSI of the channel (for example, the spatial domain vector indication information, frequency domain vector indication information, etc. of the channel) based on a long period (for example, the second period). While ensuring the accuracy of the PMI indicated by the precoding matrix, this not only improves the flexibility of the resource configuration of the reference signal, but also reduces the overhead of the time-frequency resources occupied by the reference signal.

[0203] To sum up, compared with the prior art in which the terminal device receives the first reference signal through resources with a higher frequency domain density, the terminal device in the present application receives the first reference signal through resources with a smaller frequency domain density (for example, resources of the first reference signal), which can reduce the overhead of the time-frequency resources occupied by the reference signal (for example, CSI-RS).

[0204] In a possible implementation, method 600 further includes: the terminal device receives third indication information from the network device, and accordingly, the network device sends the third indication information to the terminal device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0205] The third indication information may be DCI or MAC CE, which is not limited in this application.

[0206] For example, when the network device configures resources for the first reference signal, the DCI may instruct the terminal device to determine the first frequency domain density. The terminal device receives the first reference signal based on the first frequency domain density indicated by the DCI.

[0207] In this embodiment, compared with the network device pre-setting the first frequency domain density, the network device in this application dynamically instructs the terminal side to feedback the first frequency domain density through the third indication information (for example, DCI), which can improve the flexibility of the frequency domain density configuration.

[0208] In another possible implementation, before the terminal device receives the third indication information from the network device, method 600 also includes: the terminal device sends first indication information to the network device, and accordingly, the network device receives the first indication information from the terminal device, and the first indication information indicates the first frequency domain density.

[0209] Before the terminal device receives the third indication information, the terminal device sends the first indication information to the network device, and the first indication information indicates the first frequency domain density fed back by the terminal side; after receiving the first indication information, the network device can determine whether to use the first frequency domain density indicated by the first indication information to configure the resources of the first reference signal; if the network device uses the first frequency domain density fed back by the terminal side, the network device indicates to the terminal side through the third indication information that the first frequency domain density will be used to configure the resources of the first reference signal, so that the terminal side can promptly know on which frequency domain density of the reference signal resources to receive the reference signal and based on which reference signal to feedback the corresponding CSI; if the network device does not use the first frequency domain density fed back by the terminal side, the network device can determine the first frequency domain density based on the usage of the time-frequency resources, and configure the resources of the first reference signal according to the first frequency domain density.

[0210] In this embodiment, before receiving the third indication information sent by the network device, the terminal device feeds back an appropriate first frequency domain density to the network device to assist the network device in determining the first frequency domain density to avoid wasting time-frequency resources.

[0211] In another possible implementation, method 600 further includes: the terminal device sends second indication information to the network device, and accordingly, the network device receives the second indication information from the terminal device, where the second indication information indicates the first frequency domain density.

[0212] The terminal device sends second indication information to the network device, where the second indication information indicates the first frequency domain density fed back by the terminal side. After receiving the second indication information, the network device can configure first reference signal resources based on the first frequency domain density indicated by the second indication information. Because the terminal side estimates the channel state of the downlink channel based on the measurement results of the downlink channel, it can more accurately determine the first frequency domain density under the current channel state of the downlink channel. The network device configures first reference signal resources with a reasonable frequency domain density based on the first frequency domain density fed back by the terminal side, thereby avoiding waste of time-frequency resources.

[0213] In one possible implementation, method 600 further includes: when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the terminal device receives the first reference signal according to the resource of the second reference signal. Correspondingly, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the network device sends the second reference signal according to the resource of the second reference signal. The second CSI is measured based on the second reference signal, and the first CSI is measured based on the second reference signal.

[0214] When the network device configures the resources of the first reference signal (or the resources of the second reference signal) as the resources of the reference signal, the time-frequency position of the first reference signal indicated by the resources of the first reference signal may overlap with the time-frequency position of the second reference signal indicated by the resources of the second reference signal; when the time-frequency position of the first reference signal indicated by the resources of the first reference signal overlaps with the time-frequency position of the second reference signal indicated by the resources of the second reference signal, the terminal device will receive the second reference signal according to the resources of the second reference signal; accordingly, the network device will send the second reference signal according to the resources of the second reference signal. At this time, after receiving the second reference signal, the terminal device will measure the downlink channel according to the second reference signal to obtain the first CSI and the second CSI; the terminal device can feed back the first CSI and the second CSI to the network device.

[0215] In addition, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal does not overlap with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the terminal device executes the above method 600; for example, the terminal device receives the first reference signal from the network device based on the resource of the first reference signal; or, receives the second reference signal from the network device based on the resource of the second reference signal.

[0216] In this embodiment, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the terminal device can provide the network device with more accurate CSI based on the resource feedback CSI (for example, the first CSI and the second CSI) of the second reference signal with a larger frequency domain density, thereby helping to improve the accuracy of the network device in determining the PMI.

[0217] As shown in Figure 7, the present application provides a structural diagram of a communication device 700, which can be a terminal device, a module applied in a terminal device (such as a processor, chip, or chip system, etc.), or a logical node, logical module or software that can realize all or part of the terminal functions.

[0218] The communication device 700 includes a transceiver module 701, wherein the transceiver module 701 is used to execute the process executed by the terminal device in the above embodiment; wherein the transceiver module 701 can realize the corresponding communication function, and the transceiver module 701 can also be called a communication interface or a communication unit.

[0219] Optionally, the communication device 700 may further include a processing module, which may be configured to perform processing operations; the processing module may be implemented by at least one processor or processor-related circuits.

[0220] Optionally, the communication device 700 may further include a storage module, which may be used to store instructions and / or data, so that the communication device 700 implements the method embodiment shown in FIG. 6 .

[0221] The communication device 700 can be used to execute the actions executed by the terminal device in the above method embodiment. The transceiver module 701 is used to execute the sending-related operations or receiving-related operations on the terminal device side in the above method embodiment.

[0222] Optionally, the transceiver module 701 may include a sending module and a receiving module. The sending module is used to perform the sending operation on the terminal device side in the method embodiment shown in Figure 6. The receiving module is used to perform the receiving operation on the terminal device side in the method embodiment shown in Figure 6.

[0223] It should be noted that the communication device 700 may include a sending module but not a receiving module. Alternatively, the communication device 700 may include a receiving module but not a sending module. The specific implementation depends on whether the above solution executed by the communication device 700 includes a sending action and a receiving action.

[0224] The communication device 700 is used to execute some or all of the steps executed by the terminal device side in the embodiment shown in FIG6. For details, please refer to the relevant introduction of the embodiment shown in FIG3 above. For example, the communication device 700 can execute the following scheme:

[0225] In the communication device 700, the transceiver module 701 is configured to receive a first reference signal, wherein the first frequency domain density of the resources of the first reference signal is less than the second frequency domain density of the resources of the second reference signal; and is further configured to transmit target channel state information (CSI), wherein the target CSI includes first CSI and / or second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or the first CSI is CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal. For the specific manner in which the communication device 700 performs the method for transmitting channel state information (CSI) and the resulting beneficial effects, please refer to the relevant description of the method embodiment shown in FIG.

[0226] In the communication device 700, the transceiver module 701 is further configured to receive third indication information from the network device, where the third indication information instructs the terminal device to determine the first frequency domain density.

[0227] In the communication device 700, the transceiver module 701 is further configured to send first indication information to the network device before receiving the third indication information from the network device, where the first indication information indicates the first frequency domain density.

[0228] In the communication device 700, the transceiver module 701 is further configured to send second indication information to the network device, where the second indication information indicates the first frequency domain density. The beneficial effects of this part can be found in the above embodiments.

[0229] In the communication device 700, the transceiver module 701 is further configured to receive the second reference signal according to the resource of the second reference signal when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, wherein the second CSI is measured based on the second reference signal, and the first CSI is measured based on the second reference signal. The beneficial effects of this section can be referred to in the above embodiments.

[0230] In the communication device 700, the period of the first reference signal is the first period, the period of the second reference signal is the second period, and the first period is smaller than the second period. The beneficial effects of this part can be referred to the above embodiments.

[0231] In the communication device 700, the configuration information of the first reference signal resource also includes the number of reference signal ports, the first multiplexing type, and the first time-frequency domain position; the configuration information of the second reference signal resource also includes the number of reference signal ports, the second multiplexing type, and the second time-frequency domain position. The beneficial effects of this section can be referred to in the above embodiment.

[0232] In communication device 700, the first CSI includes linear combination coefficients corresponding to at least one of a spatial vector, a frequency vector, or a joint space-frequency vector; and the second CSI includes at least one of spatial vector indication information, frequency vector indication information, or joint space-frequency vector indication information. The beneficial effects of this section can be found in the above embodiments.

[0233] It should be understood that the specific process of each module 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.

[0234] The transceiver module 701 in the above embodiment can be implemented by a transceiver or transceiver-related circuits, wherein the transceiver includes a transmitter and / or a receiver, the transmitter is used to implement the transmission function, and the receiver is used to implement the reception function. The transceiver module 701 can also be collectively referred to as a transceiver module, a communication module, or a communication interface. The storage module can be implemented by at least one memory.

[0235] As shown in Figure 8, the present application provides a structural diagram of another communication device 800, which can be a network device (for example, a base station), or a module applied in a network device (such as a processor, chip, or chip system, etc.), or a logical node, logical module or software that can realize all or part of the functions of the network device.

[0236] The communication device 800 includes a transceiver module 801 . Optionally, the communication device 800 also includes a processing module 802 .

[0237] The transceiver module 801 can implement corresponding communication functions, and the transceiver module 801 can also be called a communication interface or a communication unit. The processing module 802 is used to perform processing operations.

[0238] Optionally, the communication device 800 may further include a storage module, which may be used to store instructions and / or data. The processing module 802 may read the instructions and / or data in the storage module so that the communication device 800 implements the method embodiment shown in FIG. 3 .

[0239] The communication device 800 can be used to perform the actions performed by the network device in the above method embodiments. The transceiver module 801 is used to perform the sending-related operations or receiving-related operations on the network device side in the above method embodiments, and the processing module 802 is used to perform the processing-related operations on the network device side in the above method embodiments.

[0240] Optionally, the transceiver module 801 may include a sending module and a receiving module. The sending module is used to perform the sending operation of the network device in the method embodiment shown in Figure 6. The receiving module is used to perform the receiving operation of the network device in the method embodiment shown in Figure 6.

[0241] It should be noted that the communication device 800 may include a sending module but not a receiving module. Alternatively, the communication device 800 may include a receiving module but not a sending module. The specific implementation depends on whether the above solution executed by the communication device 800 includes a sending action and a receiving action.

[0242] The communication device 800 is used to execute some or all of the steps executed by the network device in the embodiment shown in FIG6 . For details, please refer to the relevant introduction of the embodiment shown in FIG6 . For example, the communication device 800 can execute the following scheme:

[0243] In communication device 800, transceiver module 801 is configured to transmit a first reference signal, wherein the first frequency domain density of resources of the first reference signal is less than the first frequency domain density of resources of the second reference signal. The transceiver module 801 is further configured to receive target channel state information (CSI), wherein the target CSI includes first CSI and / or second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or the first CSI is CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal. For the specific manner in which communication device 800 performs the method for receiving channel state information (CSI) and the resulting beneficial effects, please refer to the relevant description in the method embodiment shown in FIG.

[0244] In the communication device 800, the processing module 802 is further configured to configure resources of the first reference signal and resources of the second reference signal in the first resource set. The beneficial effects of this part can be referred to the above embodiments.

[0245] In the communication device 800, the processing module 802 is further configured to configure resources for the first reference signal in the second resource set; and configure resources for the second reference signal in the third resource set, where the second resource set and the third resource set are different. The beneficial effects of this section can be referred to the above embodiments.

[0246] In the communication device 800, the transceiver module 801 is configured to send third indication information to the terminal device, where the third indication information instructs the terminal device to determine the first frequency domain density. The beneficial effects of this part can be referred to the above embodiments.

[0247] In the communication device 800, the transceiver module 801 is further configured to receive first indication information from the terminal device before sending the third indication information to the terminal device, where the first indication information indicates the first frequency domain density.

[0248] In the communication device 800, the transceiver module 801 is further configured to receive second indication information from the terminal device, where the second indication information indicates the first frequency domain density. The beneficial effects of this part can be found in the above embodiments.

[0249] In the communication device 800, the transceiver module 801 is further configured to, when the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, send the second reference signal according to the resource of the second reference signal, wherein the second CSI is measured based on the first reference signal, and the first CSI is measured based on the first reference signal. The beneficial effects of this section can be referred to the above embodiments.

[0250] In the communication device 800, the period of the first reference signal is the first period, the period of the second reference signal is the second period, and the first period is smaller than the second period. The beneficial effects of this part can be referred to the above embodiment.

[0251] In communication device 800, the configuration information for the first reference signal resource also includes the number of reference signal ports, the first multiplexing type, and the first time-frequency domain position; the configuration information for the second reference signal resource also includes the number of reference signal ports, the second multiplexing type, and the second time-frequency domain position. The beneficial effects of this section can be found in the above embodiments.

[0252] In communication device 800, the first CSI includes linear combination coefficients corresponding to at least one of a spatial vector, a frequency vector, or a joint space-frequency vector; and the second CSI includes at least one of spatial vector indication information, frequency vector indication information, or joint space-frequency vector indication information. The beneficial effects of this section can be found in the above embodiments.

[0253] It should be understood that the specific process of each module 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.

[0254] The processing module 802 in the above embodiment can be implemented by at least one processor or processor-related circuits. The transceiver module 801 can be implemented by a transceiver or transceiver-related circuits, wherein the transceiver includes a transmitter and / or a receiver, the transmitter is used to implement the transmission function, and the receiver is used to implement the reception function. The transceiver module 801 can also be collectively referred to as a transceiver module, a communication module, or a communication interface. The storage module can be implemented by at least one memory.

[0255] As shown in Figure 9, the present application provides a schematic structural diagram of another communication device 900. In one possible implementation, the communication device 900 can be a terminal device, a module (such as a processor, chip, or chip system) used in a terminal device, or a logical node, logic module, or software that can implement all or part of the terminal functions.

[0256] In another possible implementation, the communication device 900 can be a network device (e.g., a base station), or it can be executed by a module (e.g., a processor, a chip, or a chip system) applied in the network device, or it can be a logical node, logical module or software that can implement all or part of the functions of the network device.

[0257] In one possible implementation, the communication device 900 may be a chip or a chip system, where the chip system may consist of a chip or include a chip and other discrete components. When the communication device 900 is a chip, the chip includes a transceiver unit and a processing unit. The transceiver unit may be an input / output circuit or a communication interface; the processing unit may be a processor, microprocessor, integrated circuit, or logic circuit integrated on the chip. Optionally, the device used to implement the receiving function in the transceiver unit may be considered a receiving unit, corresponding to the chip's input circuit; and the device used to implement the transmitting function in the transceiver unit may be considered a transmitting unit, corresponding to the chip's output circuit. That is, the transceiver unit includes a receiving unit and a transmitting unit. Optionally, the processing module 802 in the aforementioned embodiment may specifically be the processing unit in this embodiment, and the specific implementation of the processing unit is not further described. The transceiver module 701 or transceiver module 801 in the aforementioned embodiment may specifically be the transceiver unit in this embodiment, and the specific implementation of the transceiver unit is not further described.

[0258] In one possible implementation, the communication device 900 may include a processor 910 and an interface circuit 920. The processor 910 and the interface circuit 920 communicate with each other. It is understandable that the interface circuit 920 may be a transceiver or an input / output interface, wherein the transceiver includes a transmitter and / or a receiver, the transmitter is used to implement the sending function, and the receiver is used to implement the receiving function. Optionally, the processing module 802 in the aforementioned embodiment may specifically be the processor 910 in this embodiment, and therefore the specific implementation of the processor 910 will not be repeated. The transceiver module 701 or the transceiver module 801 in the aforementioned embodiment may specifically be the interface circuit 920 in this embodiment, and therefore the specific implementation of the interface circuit 920 will not be repeated.

[0259] Optionally, the communication device 900 may further include a memory 930, wherein the memory 930 communicates with the processor 910 and the interface circuit 920 via an internal connection path. The memory 930 is used to store computer programs and instructions, and the processor 910 can execute the computer programs and instructions stored in the memory 930.

[0260] In one possible implementation, the communication device 900 is used to implement various processes and operations corresponding to the terminal device in the above method 600.

[0261] In a possible implementation, the communication device 900 is used to implement various processes and operations corresponding to the network device in the above method 600.

[0262] It should be understood that the communication device 900 can be specifically the terminal device (or network device) in the above-mentioned method 600, or it can be a chip or a chip system. Correspondingly, the interface circuit 920 can be the transceiver circuit of the chip, which is not limited here. Specifically, the communication device 900 can be used to perform the various operations and / or processes corresponding to the terminal device or network device in the above-mentioned method embodiment. Optionally, the memory 930 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type. The processor 910 can be used to execute instructions stored in the memory, and when the processor 910 executes instructions stored in the memory, the processor 910 is used to execute the various operations and / or processes corresponding to the terminal device (or network device) of method 600.

[0263] During implementation, each operation of the above method can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The operation of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the operation of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0264] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, the various operations of the above-mentioned method embodiments can be completed by hardware integrated logic circuits in the processor or instructions in the form of software. The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The various methods, operations and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The operations of the methods disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the operations of the above-mentioned method in combination with its hardware.

[0265] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0266] According to the method provided in the embodiment of the present application, the present application also provides a computer program product, which includes: computer program code, when the computer program code is run on a computer, it enables the computer to execute the various operations or processes performed by the terminal device (or network device) of the above-mentioned execution method 600.

[0267] According to the method provided in an embodiment of the present application, the present application also provides a computer-readable storage medium, which stores program code. When the program code runs on a computer, the computer executes the various operations or processes performed by the terminal device (or network device) of the above-mentioned method 600.

[0268] According to the method provided in the embodiment of the present application, the present application also provides a communication system, which includes one or more terminal devices and one or more network devices in the aforementioned method 600.

[0269] The above-mentioned various apparatus embodiments correspond completely to the method embodiments, and the corresponding modules or units perform the corresponding operations. For example, the communication unit (transceiver) performs the receiving or sending operations in the method embodiments, and other operations except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can be based on the corresponding method embodiments. There can be one or more processors.

[0270] In the embodiments of this application, each term and English abbreviation is provided for convenience of description and shall not constitute any limitation to this application. This application does not exclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0271] It should be understood that the term "and / or" as used herein describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. A and B can be singular or plural. The character " / " generally indicates an "or" relationship between the associated objects.

[0272] Those skilled in the art will appreciate that the various illustrative logical blocks and operations described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0273] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can be based on the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0274] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0275] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0276] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0277] In the above embodiments, the functions of each functional unit can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0278] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the contributing part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the operations of the methods described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0279] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents; and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for sending channel state information CSI, characterized in that: Applied to a terminal device, the method comprises: receiving a first reference signal, wherein a first frequency domain density of resources of the first reference signal is less than a second frequency domain density of resources of the second reference signal; Send target channel state information CSI, where the target CSI includes first CSI and / or second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or the first CSI is CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal.

2. The method according to claim 1, characterized in that The method further comprises: Receive third indication information from a network device, where the third indication information instructs the terminal device to determine the first frequency domain density.

3. The method according to claim 2, characterized in that Before receiving the third indication information from the network device, the method further includes: First indication information is sent to the network device, where the first indication information indicates the first frequency domain density.

4. The method according to claim 1, characterized in that The method further comprises: Second indication information is sent to a network device, where the second indication information indicates the first frequency domain density.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: When the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the second reference signal is received according to the resource of the second reference signal, the second CSI is measured according to the second reference signal, and the first CSI is measured according to the second reference signal.

6. A method for receiving channel state information CSI, characterized in that: Applied to a network device, the method comprises: Sending a first reference signal, wherein a first frequency domain density of resources of the first reference signal is less than a first frequency domain density of resources of the second reference signal; Receive target channel state information CSI, where the target CSI includes first CSI and / or second CSI, wherein the first CSI is CSI determined based on the first reference signal and the second CSI, or the first CSI is CSI determined based on the second reference signal and the second CSI, and the second CSI is CSI corresponding to the second reference signal.

7. The method according to claim 6, characterized in that The method further comprises: Resources of the first reference signal and resources of the second reference signal are configured in a first resource set.

8. The method according to claim 6, characterized in that The method further comprises: configuring resources of the first reference signal in a second resource set; The resources of the second reference signal are configured in a third resource set, and the second resource set is different from the third resource set.

9. The method according to any one of claims 6 to 8, characterized in that The method further comprises: Send third indication information to the terminal device, wherein the third indication information instructs the terminal device to determine the first frequency domain density.

10. The method according to claim 9, characterized in that Before sending the third indication information to the terminal device, the method further includes: Receive first indication information from the terminal device, where the first indication information indicates the first frequency domain density.

11. The method according to any one of claims 6 to 8, characterized in that The method further comprises: Receive second indication information from a terminal device, where the second indication information indicates the first frequency domain density.

12. The method according to any one of claims 6 to 11, characterized in that The method further comprises: When the time-frequency position of the first reference signal indicated by the resource of the first reference signal coincides with the time-frequency position of the second reference signal indicated by the resource of the second reference signal, the second reference signal is sent according to the resource of the second reference signal, the second CSI is measured according to the second reference signal, and the first CSI is measured according to the second reference signal.

13. The method according to any one of claims 1 to 12, characterized in that The method further comprises: The period of the first reference signal is a first period, the period of the second reference signal is a second period, and the first period is smaller than the second period.

14. The method according to any one of claims 1 to 13, characterized in that The configuration information of the resources of the first reference signal also includes the number of reference signal ports, a first multiplexing type and a first time-frequency domain position; the configuration information of the resources of the second reference signal also includes the number of reference signal ports, a second multiplexing type and a second time-frequency domain position.

15. The method according to any one of claims 1 to 14, characterized in that The first CSI includes linear combination coefficients corresponding to at least one of a spatial domain vector, a frequency domain vector or a spatial-frequency joint vector; the second CSI includes at least one of the spatial domain vector indication information, the frequency domain vector indication information or the spatial-frequency joint vector indication information.

16. The method according to any one of claims 1 to 15, characterized in that The first reference signal is a first channel state information reference signal CSI-RS, and the second reference signal is a second CSI-RS.

17. A communication device, characterized in that: The communication device comprises a module for executing the method according to any one of claims 1 to 5 and claims 13 to 16, or comprises a module for executing the method according to any one of claims 6 to 16.

18. A communication device, characterized in that: The communication device comprises: a processor; The processor is used to execute a computer program or instruction in the memory. When the computer program or instruction is executed by the processor, the device implements the method as claimed in any one of claims 1 to 5 and claims 13 to 16, or implements the method as claimed in any one of claims 6 to 16.

19. A computer-readable storage medium, characterized in that: The method comprises a computer program or an instruction, which, when executed on a communication device, causes the method according to any one of claims 1 to 5 and claims 13 to 16 to be executed, or causes the method according to any one of claims 6 to 16 to be executed.

20. A computer program product, characterized in that The computer program product comprises a computer program code, and when the computer program code is executed, the method according to any one of claims 1 to 5 and claims 13 to 16 is executed, or the method according to any one of claims 6 to 16 is executed.

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