Communication method, apparatus and system

Abstract

The present application relates to a communication method, apparatus and system. The method comprises: a terminal device acquiring first information, which is used for determining frequency-domain density offsets of reference signals corresponding to M ports; on the basis of the frequency-domain density offsets of the reference signals corresponding to the M ports, the terminal device determining frequency-domain densities of the reference signals corresponding to the M ports; and the terminal device sending or receiving the reference signals on the basis of the frequency-domain densities of the reference signals corresponding to the M ports. In the embodiments of the present application, frequency-domain densities can be respectively adjusted for reference signals corresponding to different ports, such that the frequency-domain density of the reference signal corresponding to each port can match factors such as channel conditions of the port, and therefore a channel estimation process can adapt to various different channel conditions, thereby facilitating an improvement in the accuracy of channel estimation.

Description

Communication method, device and system Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method, device, and system. Background Art

[0002] In massive multi-input multi-output (MIMO) systems, estimating the uplink or downlink channel becomes increasingly important for transmitting and receiving data, achieving system synchronization, and providing feedback on channel information. Channel estimation refers to the process of reconstructing or recovering the received signal to compensate for signal distortion caused by channel fading and noise fading. It uses reference signals known to the transmitter and receiver to track channel variations in the time and frequency domains. These reference signals, also known as pilot signals or reference signals (RS), are distributed across different resource elements (REs) in the two-dimensional time-frequency space within an orthogonal frequency division multiplexing (OFDM) symbol and have known amplitude and phase.

[0003] One reference signal is the demodulation reference signal (DMRS). User equipment (UE) performs channel estimation based on the received DMRS. The resulting channel estimation result can be used to assist in demodulation of the physical downlink shared channel (PDSCH). The performance of channel estimation based on DMRS is affected by factors such as the signal-to-noise ratio and the frequency domain density of the DMRS ports, resulting in poor channel estimation performance.

[0004] Summary of the Invention

[0005] Embodiments of the present application provide a communication method, apparatus, and system for improving channel estimation accuracy.

[0006] In a first aspect, a first communication method is provided. The method can be executed by a terminal device or a chip system capable of implementing the functions of the terminal device. The method includes: obtaining first information, the first information being used to determine a frequency domain density offset of reference signals corresponding to M ports, where M is a positive integer; determining the frequency domain density of the reference signals corresponding to the M ports based on the frequency domain density offset of the reference signals corresponding to the M ports; and sending or receiving a reference signal based on the frequency domain density of the reference signals corresponding to the M ports.

[0007] In an embodiment of the present application, the frequency domain density offsets of the reference signals corresponding to the M ports can be determined based on the first information. For example, the frequency domain density offsets of the reference signals corresponding to different ports are the same or different. This allows the frequency domain density to be adjusted for the reference signals corresponding to different ports, so that the frequency domain density of the reference signal corresponding to each port can be consistent with factors such as the channel conditions of the port. When performing channel estimation based on DMRS, channel estimation can be performed based on the frequency domain density of the reference signal corresponding to the corresponding port. This is equivalent to taking into account the channel conditions corresponding to the port in the channel estimation process, so that the channel estimation process can adapt to various different channel conditions, which helps to improve the accuracy of channel estimation.

[0008] In an optional embodiment, obtaining the first information includes: receiving the first information from a network device; or obtaining predefined first information. The first information may be from the network device, or may be predefined by a protocol, or may be preconfigured in the terminal device and the network device, or may be determined by negotiation between the terminal device and the network device, without limitation.

[0009] In an optional embodiment, the first information is used to indicate a mapping relationship between different modulation and coding schemes (MCS) and frequency domain density offsets of reference signals corresponding to different ports. The terminal device can independently determine the frequency domain density offset for each of the M ports based on the first information, eliminating the need for the network device to send the determined frequency domain density offset to the terminal device, thereby simplifying the implementation of the network device.

[0010] In an optional embodiment, the mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and indexes of N ports, wherein the index of each port in the N ports corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port in the N ports, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port indexes are the same or different; wherein the N ports include the M ports. This mapping relationship may also satisfy: in this mapping relationship, each port in the N ports (or each port index) may correspond to multiple MCS intervals (the multiple MCS intervals are, for example, part or all of at least one MCS interval), and under each port, each MCS interval in the multiple MCS intervals corresponds to a frequency domain density offset, wherein the frequency domain density offsets corresponding to different MCS intervals are the same or different; and / or, each MCS interval in at least one MCS interval may correspond to multiple ports (or, to multiple port indexes. The multiple ports are, for example, part or all of the N ports), and under each MCS interval, each port in the multiple ports (or, each port index) corresponds to a frequency domain density offset, wherein the frequency domain density offsets corresponding to different ports are the same or different. This mapping relationship may cover more ports, for example, the N ports are all or part of the ports corresponding to the terminal device and the network device, or, in addition to including all or part of the ports corresponding to the terminal device and the network device, the N ports may also include all or part of the ports corresponding to other terminal devices and / or other network devices. In the first information, one or more MCS intervals may correspond to a frequency domain density offset, wherein an MCS interval may include one or more values ​​of MCS, thereby simplifying the mapping relationship and reducing the storage space occupied by the mapping relationship.

[0011] In an optional embodiment, the first information is used to indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, wherein one port group includes one or more of the M ports. The terminal device can determine the frequency domain density offset of each of the M ports by itself based on the first information, and the network device does not need to send the determined frequency domain density offset to the terminal device, which can simplify the implementation of the network device. Moreover, the mapping relationship with the frequency domain density offset can be a port, or a port group. For example, if the ports in a port group have the same or similar characteristics (such as similar channel conditions, etc.), then a port group can have a mapping relationship with the frequency domain density offset as a whole, thereby simplifying the mapping relationship.

[0012] In an optional embodiment, the mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and an index of at least one port group, wherein the index of each port group in the at least one port group corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port group in the at least one port group, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port group indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port group indexes are the same or different, and the at least one port group includes N ports, and the N ports include the M ports. The mapping relationship may also satisfy: in the mapping relationship, each port group in at least one port group (or, each port group index) may correspond to multiple MCS intervals (the multiple MCS intervals are, for example, part or all of at least one MCS interval), and under each port group, each MCS interval in the multiple MCS intervals corresponds to a frequency domain density offset, wherein the frequency domain density offsets corresponding to different MCS intervals are the same or different; and / or, each MCS interval in at least one MCS interval may correspond to multiple port groups (or, correspond to multiple port group indexes. The multiple port groups are, for example, part or all of at least one port group), and under each MCS interval, each port group in the multiple ports (or, each port group index) corresponds to a frequency domain density offset, wherein the frequency domain density offsets corresponding to different port groups are the same or different.

[0013] In an optional implementation, for a single port among the N ports, a larger MCS corresponding to the port corresponds to a larger frequency domain density offset (or frequency domain density) of a reference signal corresponding to the port; or, a smaller MCS corresponding to the port corresponds to a smaller frequency domain density offset (or frequency domain density) of the reference signal corresponding to the port. This is only one example of a relationship between an MCS and a reference signal frequency domain density offset and is not limited thereto.

[0014] In an optional implementation, a sum of frequency domain density offsets of reference signals corresponding to N ports is less than or equal to a first threshold, where the N ports include the M ports. Optionally, the first threshold is 0, that is, the sum of frequency domain density offsets of reference signals corresponding to the N ports is 0, indicating that the overall overhead of the reference signal does not need to change before and after the frequency domain density adjustment. In this case, without increasing the reference signal overhead, this embodiment of the present application can improve channel estimation accuracy.

[0015] In an optional embodiment, the method further includes: receiving downlink control information from the network device, the downlink control information being used to indicate one or more MCSs, the one or more MCSs corresponding to the M ports; and determining, based on the one or more MCSs and the mapping relationship indicated by the first information, the frequency domain density offset of the reference signal corresponding to some or all of the M ports. This embodiment provides a specific way for a terminal device to determine the frequency domain density offset (or, frequency domain density), that is, the terminal device can determine the frequency domain density offset corresponding to some or all of the M ports in combination with the first information and the MCS indicated by the downlink control information, so that the terminal device can further determine the frequency domain density of the reference signal corresponding to some or all of the M ports.

[0016] In an optional embodiment, the first information is used to indicate the frequency domain density of the reference signal corresponding to each of the M ports; or, the first information is used to indicate the frequency domain density offset of the reference signal corresponding to each of the M ports. In the aforementioned scheme, the first information can indicate the mapping relationship between the MCS and the frequency domain density offset of the reference signal, and the terminal device determines the frequency domain density of the reference signal corresponding to some or all of the M ports by itself; and in this embodiment, the frequency domain density or frequency domain density offset of the reference signal corresponding to some or all of the M ports can be determined by the network device, and the network device can send the determined frequency domain density or frequency domain density offset to the terminal device, so that the terminal device does not need to perform the determination step, which can simplify the implementation of the terminal device and is more conducive to making the final frequency domain density determined by the terminal device and the network device consistent.

[0017] In an optional embodiment, the first information is also used to indicate the frequency domain resource position mapped by the reference signal corresponding to each of the M ports; or, the frequency domain resource position mapped by the reference signal corresponding to each of the M ports is predefined. The embodiment of the present application adjusts the frequency domain density of the reference signal corresponding to some or all of the M ports. After the frequency domain density of the reference signal corresponding to a port changes, the frequency domain resource position of the reference signal corresponding to the port may also change. The first information can also indicate the changed frequency domain resource position, so the frequency domain resource mapped by the reference signal can be more flexible; or, the frequency domain resource position mapped by the reference signal corresponding to each of the M ports can also be predefined by the protocol, or preconfigured by the network device, thereby reducing the overhead of the first information.

[0018] In an optional embodiment, the method further includes: sending capability information of the terminal device to the network device, where the capability information indicates whether the terminal device supports adjustment of the frequency domain density of the M ports, or indicates a maximum and minimum frequency domain density offset supported by each of the M ports. The terminal device may send the capability information to the network device so that the frequency domain density can be adjusted in accordance with the capabilities or needs of the terminal device.

[0019] In an optional embodiment, the difference between the first frequency domain density and the second frequency domain density is less than or equal to a second threshold value, wherein the first frequency domain density is the sum of the frequency domain densities corresponding to the M ports determined based on the frequency domain density offset of the reference signal corresponding to the M ports, and the second frequency domain density is the sum of the initial frequency domain densities corresponding to the M ports. Optionally, if the second threshold value is 0, the difference between the first frequency domain density and the second frequency domain density may be 0, indicating that the overall overhead of the reference signal has not changed. In this case, without increasing the reference signal overhead, the embodiment of the present application can improve the channel estimation accuracy.

[0020] In an optional embodiment, when the first frequency domain density is less than the second frequency domain density, the method further includes: sending or receiving data through a first reference signal resource, wherein the first reference signal resource is a reference signal resource corresponding to the difference between the second frequency domain density and the first frequency domain density. The first frequency domain density is less than the second frequency domain density, indicating that after adjusting the frequency domain density of the reference signal corresponding to some or all of the M ports, the overall frequency domain density is reduced. Therefore, a portion of the resources originally used to send the reference signal (for example, called the first reference signal resource, which can be understood as the resource corresponding to the absolute value of the difference between the first frequency domain density and the second frequency domain density) is no longer used to send the reference signal. Then, the terminal device can use the first reference signal resource to send or receive data to improve resource utilization.

[0021] In a second aspect, a second communication method is provided. This method can be performed by a network device or a chip system capable of implementing the functions of the network device. The method includes: determining the frequency domain density of the reference signals corresponding to the M ports based on the frequency domain density offsets of the reference signals corresponding to the M ports, where M is a positive integer; and receiving or sending reference signals based on the frequency domain density of the reference signals corresponding to the M ports.

[0022] In an optional embodiment, the method further includes: acquiring predefined first information; or sending first information to a terminal device, where the first information is used to determine a frequency domain density offset of a reference signal corresponding to the M ports.

[0023] In an optional implementation manner, the first information is used to indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different ports.

[0024] In an optional embodiment, the mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and indexes of N ports, wherein the index of each port in the N ports corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port in the N ports, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port indexes are the same or different; wherein the N ports include the M ports.

[0025] In an optional implementation, the first information is used to indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, where one port group includes one or more ports of the M ports.

[0026] In an optional embodiment, the mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and an index of at least one port group, wherein the index of each port group in the at least one port group corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port group in the at least one port group, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port group indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port group indexes are the same or different; wherein, the at least one port group includes N ports, and the N ports include the M ports.

[0027] In an optional embodiment, for the same port among the N ports, the larger the MCS corresponding to the port, the larger the frequency domain density offset of the reference signal corresponding to the port; or, the smaller the MCS corresponding to the port, the smaller the frequency domain density offset of the reference signal corresponding to the port.

[0028] In an optional implementation, a sum of frequency domain density offsets of reference signals corresponding to N ports is less than a first threshold, wherein the N ports include the M ports.

[0029] In an optional embodiment, the method further includes: sending downlink control information to the terminal device, the downlink control information being used to indicate one or more MCSs, the one or more MCSs corresponding to the M ports, wherein the one or more MCSs and the mapping relationship indicated by the first information are used to determine the frequency domain density bias of the reference signal corresponding to some or all of the M ports.

[0030] In an optional embodiment, the first information is used to indicate the frequency domain density of the reference signal corresponding to each of the M ports; or, the first information is used to indicate the frequency domain density offset of the reference signal corresponding to each of the M ports.

[0031] In an optional embodiment, the first information is further used to indicate the frequency domain resource position mapped to the reference signal corresponding to each port of the M ports; or, the frequency domain resource position mapped to the reference signal corresponding to each port of the M ports is predefined.

[0032] In an optional embodiment, capability information is received from the terminal device, where the capability information is used to indicate whether the terminal device supports adjusting the frequency domain density of the M ports, or the capability information is used to indicate the maximum and minimum values ​​of the frequency domain density offset supported by each of the M ports.

[0033] In an optional embodiment, the difference between the first frequency domain density and the second frequency domain density is less than a second threshold, wherein the first frequency domain density is the sum of the frequency domain densities corresponding to the M ports determined based on the frequency domain density offset of the reference signals corresponding to the M ports, and the second frequency domain density is the sum of the initial frequency domain densities corresponding to the M ports.

[0034] In an optional embodiment, when the first frequency domain density is less than the second frequency domain density, the method further includes: receiving or sending data through a first reference signal resource, wherein the first reference signal resource is a reference signal resource corresponding to the difference between the second frequency domain density and the first frequency domain density.

[0035] Regarding the technical effects brought about by the second aspect or some optional implementation methods, reference may be made to the introduction to the technical effects of the first aspect or corresponding implementation methods.

[0036] In a third aspect, a communication device is provided. The communication device has the function of implementing the behavior of the method embodiment described in any one of the first to second aspects above. The beneficial effects can be found in the above description and will not be repeated here.

[0037] The communication device can implement the functions of the terminal device described in any one of the first to second aspects above, for example, the communication device is the terminal device described in any one of the first to second aspects above, or is an electronic device configured in the terminal device (for example, a chip system), or is a larger device including the terminal device. The terminal device includes corresponding means (means) or modules for executing the above method. Alternatively, the communication device can implement the functions of the network device described in any one of the first to second aspects above, for example, the communication device can be the network device described in any one of the first to second aspects above, or is an electronic device configured in the network device (for example, a chip system), or is a larger device including the network device. The network device includes corresponding means or modules for executing the above method. For example, the communication device: includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module).

[0038] When the communication device is capable of implementing the functions of the terminal equipment described in any one of the first to second aspects above, in one example, the processing unit is used to obtain first information, and the first information is used to determine the frequency domain density offset of the reference signal corresponding to M ports, where M is a positive integer; the processing unit is also used to determine the frequency domain density of the reference signal corresponding to the M ports based on the frequency domain density offset of the reference signal corresponding to the M ports; and the transceiver unit is used to send or receive a reference signal based on the frequency domain density of the reference signal corresponding to the M ports.

[0039] When the communication device is capable of implementing the functions of the network equipment described in any one of the first to second aspects above, in one example, the processing unit is used to determine the frequency domain density of the reference signals corresponding to the M ports based on the frequency domain density offset of the reference signals corresponding to the M ports, where M is a positive integer; and the transceiver unit is used to receive or send the reference signal based on the frequency domain density of the reference signals corresponding to the M ports.

[0040] In an optional implementation, the communication device includes a storage unit, and the processing unit can be coupled to the storage unit and execute the program or instructions in the storage unit, so as to enable the communication device to perform the functions of the above-mentioned terminal device or network device.

[0041] In an optional embodiment, the communication device includes a processor coupled to a memory, configured to execute instructions in the memory to implement the method performed by the terminal device or network device described in any of the first and second aspects above. Optionally, the communication device also includes other components, such as an antenna, an input / output module, an interface, etc. These components may be hardware, software, or a combination of software and hardware.

[0042] In a fourth aspect, a communication device is provided, which may be a terminal device, or a chip or chip system used in a terminal device. Alternatively, the communication device may be a network device, or a chip or chip system used in a network device. The communication device includes a communication interface and a processor, and optionally, further includes a memory. Optionally, the communication interface includes a sending port and / or a receiving port; or, optionally, the communication interface is a transceiver, and the transceiver can implement a sending function and / or a receiving function. The memory is used to store a computer program, and the processor is coupled to the memory and the communication interface. When the processor reads the computer program or instruction, the communication device executes the method performed by the terminal device or network device in any of the first to second aspects above.

[0043] In a fifth aspect, a communication device is provided, which may be a terminal device, or a chip or chip system used in a terminal device. Alternatively, the communication device may be a network device, or a chip or chip system used in a network device. The communication device includes a processor and, optionally, a memory. The memory is used to store a computer program, and the processor is coupled to the memory and a communication interface. When the processor reads the computer program or instruction, the communication device executes the method performed by the terminal device or network device in any one of the first to second aspects above. Optionally, the communication device also includes a communication interface. Optionally, the communication interface includes a sending port and / or a receiving port; or, optionally, the communication interface is a transceiver, which can implement a sending function and / or a receiving function.

[0044] In a sixth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium is used to store a computer program, and when the computer program is run on a computer, the computer is caused to execute the method described in any one of the first to second aspects.

[0045] In a seventh aspect, a computer program product is provided, comprising a computer program, which, when executed on a computer, enables the computer to execute the method as described in any one of the first to second aspects.

[0046] In an eighth aspect, a chip system is provided, comprising a processor and an interface, wherein the processor is used to call and run instructions from the interface, and when the processor executes the instructions, the method described in any one of the first to second aspects is implemented.

[0047] In a ninth aspect, a communication system is provided, comprising a terminal device and a network device. The terminal device can implement the method performed by the terminal device in any of the first or second aspects, and the network device can implement the method performed by the network device in any of the first or second aspects. Optionally, the terminal device can be implemented using the communication apparatus described in the third or fourth aspect; the network device can be implemented using the communication apparatus described in the third or fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figures 1A and 1B are schematic diagrams of two types of NR DMRS;

[0049] FIG2 is a schematic diagram of a communication network architecture used in an embodiment of the present application;

[0050] FIG3 is a flow chart of a communication method provided in an embodiment of the present application;

[0051] FIG4A is a schematic diagram showing the relationship between the frequency domain density of a reference signal and the MCS at a specific port, provided by an embodiment of the present application;

[0052] FIG4B is a schematic diagram illustrating how the maximum MCS varies with the frequency domain density of the reference signal at a specific port or port group, provided by an embodiment of the present application;

[0053] FIG5A shows the frequency domain resource positions to which the reference signals are mapped when the frequency domain density of the reference signals corresponding to M ports is the initial frequency domain density in an embodiment of the present application;

[0054] FIG5B shows the frequency domain resource positions to which the reference signals are mapped when the frequency domain density of the reference signals corresponding to the M ports is the adjusted frequency domain density in an embodiment of the present application;

[0055] FIG6 is a schematic diagram showing the relationship between the interpolation filtering performance of the Wiener filter and the frequency domain density of the reference signal;

[0056] FIG7 is a schematic diagram of a device provided in an embodiment of the present application;

[0057] FIG8 is a schematic diagram of another device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0059] In the embodiments of the present application, the number of nouns, unless otherwise specified, means "singular noun or plural noun", that is, "one or more". "At least one" means one or more, and "plural" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. For example, A / B means: A or B. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0060] The ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish between multiple objects, and are not used to limit the size, content, order, timing, priority or importance of multiple objects. For example, the first frequency domain density and the second frequency domain density can be the same frequency domain density or different frequency domain densities, and this name does not indicate that the reference signals, corresponding ports, application scenarios, priorities or importance corresponding to the two frequency domain densities are different. In addition, the numbering of the steps in the various embodiments introduced in this application is only to distinguish different steps, and is not used to limit the order between the steps. For example, S302 may occur before S303, or may occur after S303, or may occur at the same time as S303.

[0061] Below, some terms or concepts in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0062] In the embodiment of the present application, the terminal device is a device with wireless transceiver function, which can be a fixed device, a mobile device, a handheld device (such as a mobile phone), a wearable device, an in-vehicle device, or a wireless device built into the above device (such as a communication module, a modem, or a chip system, etc.). The terminal device is used to connect people, objects, machines, etc., and can be widely used in various scenarios, such as but not limited to the following scenarios: sensing scenarios, cellular communications, device-to-device communication (D2D), vehicle to everything (V2X), machine-to-machine / machine-type communications (M2M / MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots and other scenarios. The terminal device may sometimes be referred to as UE, terminal, access station, UE station, remote station, wireless communication device, or user equipment, etc.

[0063] In the embodiments of the present application, the communication device for implementing the terminal device function may be a terminal device, or may be a device capable of supporting the terminal device to implement the function, such as a chip system, which may be installed in the terminal device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the terminal device as an example in which the device for implementing the terminal device function is a terminal device. In addition, for ease of description, the terminal device in the embodiments of the present application is described by taking a UE as an example.

[0064] The network devices in the embodiments of the present application include, for example, access network devices, and / or core network devices. The access network device is a device with wireless transceiver functions, which is used to communicate with the terminal device. The access network devices include but are not limited to base stations (base transceiver station (BTS), node B (Node B), evolved node B (eNodeB) / eNB, or the next generation node B (gNodeB) / gNB), transmission reception points (TRP), base stations subsequently evolved by the third generation partnership project (3GPP), access nodes in wireless fidelity (Wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, etc. The base station can be: a macro base station, a micro base station, a pico base station, a small station, a relay station, etc. Multiple base stations can support networks with the same access technology, or they can support networks with different access technologies. The base station can include one or more co-station or non-co-station transmission and receiving points. The access network device may also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network device may also be a server, etc. For example, the network device in the V2X technology may be a road side unit (RSU). The following describes the access network device using a base station as an example. The base station can communicate with the terminal device, or it can communicate with the terminal device through a relay station. The terminal device can communicate with multiple base stations in different access technologies. The core network device is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the devices that implement core network functions in systems with different access technologies may be different, and the embodiments of the present application are not limited to this. Taking the fifth generation mobile communication technology (5G) system as an example, the core network equipment includes: access and mobility management function (AMF), session management function (SMF), policy control function (PCF) or user plane function (UPF), etc.

[0065] In the CU-DU architecture, the access network equipment may include one or more logical network elements such as a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU may be configured separately or included in the same network element, such as a baseband unit (BBU). The RU may be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0066] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (ORAN) system, CU may also be referred to as open (open, O)-CU, DU may also be referred to as O-DU, CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. For the convenience of description, the embodiments of the present application are described by taking CU, CU-CP, CU-UP, DU and RU as examples. Any of the CU (or CU-CP, CU-UP), DU and RU in the embodiments of the present application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0067] In the embodiments of the present application, the communication device for implementing the network device function may be a network device, or may be a device capable of supporting the network device to implement the function, such as a chip system, which may be installed in the network device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the network device as an example of the device for implementing the network device function being a network device.

[0068] The following describes the technical features involved in the embodiments of this application.

[0069] In massive MIMO, estimating the uplink or downlink channel becomes increasingly important for transmitting and receiving data, achieving system synchronization, and providing feedback on channel information. Channel estimation refers to the process of reconstructing or recovering the received signal to compensate for signal distortion caused by channel fading and noise fading. It uses reference signals known to the transmitter and receiver to track channel variations in the time and frequency domains. These reference signals, also known as pilot signals or reference signals, are distributed across different subcarriers in the frequency domain within an OFDM symbol and have known amplitude and phase. One such reference signal is the DMRS. The UE performs channel estimation based on the received DMRS, and the resulting channel estimation results can be used to assist in PDSCH demodulation.

[0070] The sparseness of the time-frequency resources of reference signals is one of the main ways to achieve a higher number of transmission streams.

[0071] The new radio (NR) DMRS Type I and Type II in the R15 version support a maximum of 8 DMRS ports and 12 DMRS ports, respectively, with corresponding frequency domain densities of 3 REs per resource block (RB) and 2 REs per RB, respectively. Please refer to Figures 1A and 1B, which are schematic diagrams of Type I and Type II, respectively. In Figures 1A and 1B, the shaded boxes with different filling contents represent different DMRS port groups. For example, Figure 1A shows Type I, which supports a maximum of 8 DMRS ports. Taking the support of 4 DMRS ports as an example, these 4 DMRS ports can be divided into two DMRS port groups, where each DMRS port group includes 2 DMRS ports. The two DMRS port groups are shown as the two shaded boxes with different fillings in Figure 1A. Figure 1B shows Type II, which supports a maximum of 12 DMRS ports. Taking 12 DMRS ports as an example, these 12 DMRS ports can be divided into three DMRS port groups, each of which includes four DMRS ports. These three DMRS port groups are represented by the four different shaded boxes in Figure 1B. In Figures 1A and 1B, the horizontal axis represents time and the vertical axis represents frequency. Each box represents an OFDM symbol and an RE consisting of a subcarrier.

[0072] The characteristics of DMRS used for demodulating PDSCH include:

[0073] 1. It is divided into front-loaded (FL) DMRS and add-on DMRS. FL DMRS occupies 1 to 2 OFDM symbols, for example, OFDM symbols 2 and 3 within a time slot. When FL DMRS occupies 2 OFDM symbols, add-on DMRS occupies 0 to 2 OFDM symbols. When FL DMRS occupies 1 OFDM symbol, add-on DMRS occupies 0 to 3 OFDM symbols.

[0074] 2. The DMRS is regularly mapped to each scheduling unit, for example, a physical resource block (PRB) pair. The DMRS transmitted on each DMRS port is mapped to each scheduled scheduling unit. Furthermore, the DMRS transmitted on each DMRS port is mapped to each scheduled time slot.

[0075] 3. DMRS PRB bundling: Consecutive PRBs are bundled together or grouped together as a precoding resource block group (PRG). The transmitter and receiver can perform joint frequency-domain processing on a bundle or a PRG. This approach improves reception performance.

[0076] 4. DMRS rate matching: The base station can indicate to the UE which DMRS ports are occupied, and the unoccupied DMRS ports can be used to transmit data.

[0077] Currently, DMRS eType I and eType II are being promoted. These two types of DMRS support a maximum of 16 and 24 DMRS ports, respectively, with corresponding frequency domain densities of 3 reference signals (REs) per 2 resource blocks (RBs) and 1 RE per RB. As can be seen, the frequency domain densities of eType I and eType II are halved compared to those of Type I and Type II, respectively. The same frequency domain density is used for all DMRS ports. When reference signals become sparse in the frequency domain, channel estimation accuracy is affected, ultimately reducing the spectral efficiency of massive MIMO.

[0078] In view of this, the embodiment of the present application can determine the frequency domain density offset of the reference signals corresponding to the M ports based on the first information. For example, the frequency domain density offsets of the reference signals corresponding to different ports are the same or different. This makes it possible to adjust the frequency domain density for the reference signals corresponding to different ports separately, so that the frequency domain density of the reference signal corresponding to each port can be consistent with factors such as the channel conditions of the port. When performing channel estimation based on DMRS, channel estimation can be performed based on the frequency domain density of the reference signal corresponding to the corresponding port. This is equivalent to taking into account the channel conditions corresponding to the port in the channel estimation process, so that the channel estimation process can adapt to various different channel conditions, which helps to improve the accuracy of channel estimation.

[0079] The technical solutions provided in the embodiments of the present application can be applied to the fourth generation mobile communication technology (the 4th generation, 4G) system, such as the long term evolution (long term evolution, LTE) system, or can be applied to the fifth generation mobile communication technology (the 5th generation, 5G) system, such as the NR system, or can also be applied to the next generation mobile communication system or other similar communication systems, such as the sixth generation mobile communication technology (the 6th generation, 6G) system, etc., without specific limitation. In addition, the technical solutions provided in the embodiments of the present application can be applied to D2D scenarios, such as NR-D2D scenarios, etc., or can be applied to V2X scenarios, such as NR-V2X scenarios, etc. For example, it can be used in the fields of factory manufacturing, whole-house intelligence, intelligent driving, assisted driving, or intelligent connected vehicles.

[0080] Reference is made to Figure 2, which illustrates a communication network architecture applicable to embodiments of the present application. Figure 2 includes a UE and a network device. The network device can transmit reference signals and receive reference signals from the UE; the UE can receive reference signals from the network device and send reference signals to the network device. The UE and network device are capable of executing the methods provided in embodiments of the present application.

[0081] In order to better introduce the embodiments of the present application, the method provided by the embodiments of the present application is described below in conjunction with the accompanying drawings. In each embodiment of the present application, "port" may refer to a "reference signal port". In each embodiment of the present application, the reference signal includes, for example, a DMRS or other reference signal, such as a sounding reference signal (SRS). Among them, the DMRS may include an uplink DMRS or a downlink DMRS. Unless otherwise specified below, the steps represented by dotted lines in the accompanying drawings corresponding to the various embodiments of the present application are all optional steps.

[0082] The methods provided in each embodiment of the present application can be applied to the network architecture shown in Figure 2. For example, the UE involved in each embodiment of the present application can be the UE in Figure 2; the network device involved in each embodiment of the present application can be the network device in Figure 2.

[0083] An embodiment of the present application provides a communication method. Please refer to Figure 3, which is a flowchart of the method.

[0084] S301: A UE sends its capability information to a network device, and the network device receives the capability information accordingly.

[0085] Optionally, the network device may be an integrated architecture or a distributed architecture, for example, the network device includes a CU and / or a DU, or includes one or more of a CU-CP, a CU-UP, or a DU. When the network device includes a DU, the network device receives the capability information from the UE, specifically, the DU included in the network device receives the capability information from the UE. Optionally, the network device including the DU may also include a CU; or, the network device including the DU may also include a CU-CP and / or a CU-UP.

[0086] The capability information of the UE may indicate the channel processing capability of the UE, and / or indicate other capabilities of the UE. For example, the channel processing capability of the UE may characterize or indicate one or more of the following: whether the UE supports adjusting the frequency domain density of M ports (for example, it can be uniformly indicated for the M ports, or it can be separately indicated for different ports in the M ports), whether the UE supports adjusting the frequency domain density of at least one port group (for example, it can be uniformly indicated for at least one port group, or it can be separately indicated for different port groups in at least one port group. The at least one port group may include M ports), or the maximum value and / or minimum value of the frequency domain density offset supported by the UE for each port in the M ports. The maximum value and / or minimum value of the frequency domain density offset supported by the UE for a certain port in the M ports can be understood as the adjustment range of the frequency domain density supported by the UE for the port, that is, the range within which the UE supports adjusting the frequency domain density. For example, for port #1, the maximum value of the frequency domain density offset supported by the UE is +1RE / 2RB, and the minimum value is -2RE / 2RB, indicating that the adjustment range of the frequency domain density supported by the UE for port #1 is [-2, 1]RE / 2RB. Optionally, if the channel processing capability of the UE characterizes or indicates the maximum value and / or minimum value of the frequency domain density offset supported by the UE for each of the M ports, the channel processing capability of the UE may no longer indicate whether the UE supports adjustment of the frequency domain density of the M ports or at least one port group.

[0087] Optionally, the M ports are, for example, all or part of the ports corresponding to the UE. If the M ports are part of the ports corresponding to the UE, then optionally, the capability information may indicate one or more of the following: whether the UE supports adjusting the frequency domain density of all ports corresponding to the UE, whether the UE supports adjusting the frequency domain density of at least one port group (at least one port group may include all ports supported by the UE), or the maximum and / or minimum value of the frequency domain density offset supported by the UE for each port of all ports supported by the UE.

[0088] Optionally, the M ports are, for example, all or part of the ports corresponding to the network device. If the M ports are part of the ports corresponding to the network device, then optionally, the capability information may indicate one or more of the following: whether the UE supports adjusting the frequency domain density of all ports corresponding to the network device, whether the UE supports adjusting the frequency domain density of at least one port group (at least one port group may include all ports supported by the network device), or the maximum and / or minimum value of the frequency domain density offset supported by the UE for each port of all ports supported by the network device.

[0089] Alternatively, the UE may not send the capability information of the UE to the network device, so S301 is an optional step.

[0090] S302. The UE obtains first information. The first information may be used to determine frequency domain density offsets for reference signals corresponding to M ports, where M is a positive integer. The frequency domain density offset may be used to adjust the frequency domain density and may be referred to as a frequency domain density adjustment, a frequency domain density offset, or a frequency domain density correction, without limitation. The reference signal corresponding to a port may be, for example, a reference signal received or transmitted via the port.

[0091] The UE can obtain the first information in different ways. For example, one optional way for the UE to obtain the first information is that the network device sends the first information, and the UE receives the first information from the network device. In this way, the first information can be determined by the network device, which has a certain degree of implementation flexibility. For another example, another optional way for the UE to obtain the first information is that the UE obtains predefined or preconfigured first information. For example, if the first information is predefined by a protocol, or can also be preconfigured in the UE, the UE can obtain the first information according to the protocol or according to the preconfigured information. In addition to this, the UE can also obtain the first information in other ways, which are not limited.

[0092] Optionally, the network device may be an integrated architecture or a distributed architecture, for example, the network device includes a CU and / or a DU, or includes one or more of a CU-CP, a CU-UP, or a DU. When the network device includes a DU, the network device sends the first information to the UE, specifically, the DU included in the network device sends the first information to the UE. Optionally, the network device including the DU may further include a CU; or, the network device including the DU may further include a CU-CP and / or a CU-UP.

[0093] The UE may determine the frequency domain density offsets of the reference signals corresponding to the M ports according to the first information. To achieve this purpose, the first information may be implemented in different ways.

[0094] As an optional implementation of the first information, the first information may indicate the mapping relationship between different MCSs and the frequency domain density offsets of the reference signals corresponding to different ports, or the first information may indicate the mapping relationship between the MCS, the index of each port in the N ports, and the frequency domain density offset of the reference signal corresponding to each port. In this case, the first information can be regarded as configuration information. Optionally, the "port" in the content indicated by the first information can also be replaced by "stream" or "transport layer (layer)," etc., without limitation. N is a positive integer, for example, N ports include M ports. Optionally, the N ports may include all or part of the ports of each UE in one or more UEs, and / or, include all or part of the ports of each network device in one or more network devices. The UE is one of the one or more UEs, and the network device is one of the one or more network devices.

[0095] For example, the mapping relationship may include a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and the indexes of N ports. For example, in the mapping relationship, the index of each port in the N ports corresponds to at least one MCS interval; and, among the MCS intervals and frequency domain density offsets corresponding to one port in the N ports, the frequency domain density offsets corresponding to different MCS intervals are the same or different, wherein, if the frequency domain density offsets corresponding to different MCS intervals are different, it can be considered that the MCS interval and the frequency domain density offset are in one-to-one correspondence; and, among the port index and frequency domain density offsets corresponding to one MCS interval in at least one MCS interval, the frequency domain density offsets corresponding to different port indexes are the same or different, wherein, if the frequency domain density offsets corresponding to different port indexes are different, it can be considered that the port index and the frequency domain density offset are in one-to-one correspondence. Optionally, the index of a port may represent the signal-to-noise ratio corresponding to the port. For example, the index of any one of the N ports may correspond to a signal-to-noise ratio interval, and the signal-to-noise ratios included in the signal-to-noise ratio interval are all signal-to-noise ratios corresponding to the port. The signal-to-noise ratio intervals corresponding to different ports may have an intersection or may not have an intersection. Alternatively, the index of a port may represent the ratio between the channel gain corresponding to the port and the cell noise floor. For example, the index of any one of the N ports may correspond to a ratio interval, and the ratios included in the ratio interval are all ratios corresponding to the port. The ratio intervals corresponding to different ports may have an intersection or may not have an intersection.

[0096] For example, refer to Table 1, which is an example of the mapping relationship. The mapping relationship, for example, includes one or more items in Table 1, where in Table 1, a port index, an MCS interval, and a frequency domain density offset may constitute a set of mapping relationships. It can be seen that Table 1 includes multiple sets of mapping relationships, and the mapping relationship indicated by the first information, for example, includes some or all of the mapping relationships in the multiple sets of mapping relationships shown in Table 1.

[0097] Table 1

[0098] For example, in Table 1, each port (or each port index) may correspond to multiple MCS intervals. Under each port, each of the multiple MCS intervals corresponds to a frequency domain density offset, where the frequency domain density offsets corresponding to different MCS intervals are the same or different. This property may be satisfied by any row in Table 1. For another example, in Table 1, each MCS interval may correspond to multiple ports (or multiple port indexes). Under each MCS interval, each of the multiple ports (or each port index) corresponds to a frequency domain density offset, where the frequency domain density offsets corresponding to different ports are the same or different. This property may be satisfied by any column in Table 1.

[0099] Table 1 takes 24 ports as an example. In Table 1, for port #1, when the MCS value is in the range greater than or equal to 0 and less than or equal to 4, the corresponding frequency domain density offset is -2RE / 2RB. Among them, -2RE / 2RB means that the frequency domain density offset for every 2 RBs is -2RE. This frequency domain density offset can be subtracted from the initial frequency domain density to obtain the adjusted frequency domain density. The understanding of other mapping relationships in Table 1 is similar. Among them, if a frequency domain density offset is 0, it means that there is no need to adjust the frequency domain density. For example, in Table 1, the MCS intervals corresponding to port #1 include MCS 0 to MCS 4, MCS 5 to MCS 10, MCS 11 to MCS 19, and MCS 20 to MCS 27. The frequency domain density offsets corresponding to port #1 include -2RE / 2RB, -1RE / 2RB, 0, and +1RE / 2RB. For port #1, these frequency domain density offsets correspond one-to-one with the MCS intervals listed above. As can be seen, different MCS intervals correspond to different frequency domain density offsets in the MCS intervals and frequency domain density offsets corresponding to port #1. For another example, in Table 1, the port indexes corresponding to MCS 0 to MCS 4 include 1 to 24, and the frequency domain density offsets corresponding to MCS 0 to MCS 4 include -2RE / 2RB, -1RE / 2RB, ..., 0. In the range of MCS 0 to MCS 4, these frequency domain density offsets correspond one-to-one to the ports 1 to 24. It can be seen that among the port indexes and frequency domain density offsets corresponding to MCS 0 to MCS 4, different port indexes may correspond to the same or different frequency domain density offsets (some frequency domain density offsets, not shown, may have the same frequency domain density offset).

[0100] As another optional implementation of the first information, the first information may indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, or the first information may indicate a mapping relationship between an MCS, an index of each port group in at least one port group, and a frequency domain density offset of a reference signal corresponding to each port group. In this case, the first information may be regarded as configuration information. A port group may include one or more ports, for example, at least one port group includes N ports, which may be understood as including the N ports in all ports included in all port groups in at least one port group, wherein the N ports may belong to one port group in at least one port group, or may be distributed in multiple port groups in at least one port group. The number of ports included in different port groups may be the same or different.

[0101] For example, the mapping relationship may include a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and an index of at least one port group. For example, in the first information, the index of each port group in the at least one port group corresponds to at least one MCS interval; and, in the MCS interval and frequency domain density offset corresponding to one port group in the at least one port group, the frequency domain density offsets corresponding to different MCS intervals are the same or different, wherein, if the frequency domain density offsets corresponding to different MCS intervals are different, then it can also be considered that the MCS interval and the frequency domain density offset are in a one-to-one correspondence; and, in the port group index and frequency domain density offset corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port group indexes are the same or different, wherein, if the frequency domain density offsets corresponding to different port group indexes are different, then it can also be considered that the port group index and the frequency domain density offset are in a one-to-one correspondence. Optionally, the index of a port group can represent the signal-to-noise ratio corresponding to the port group. For example, the index of any port group in at least one port group can correspond to a signal-to-noise ratio interval, and the signal-to-noise ratios included in the signal-to-noise ratio interval are all the signal-to-noise ratios corresponding to the port group. The signal-to-noise ratio intervals corresponding to different port groups may have an intersection or may not have an intersection. Alternatively, the index of a port group can represent the ratio between the channel gain corresponding to the port group and the cell noise floor. For example, the index of any port group in at least one port group can correspond to a ratio interval, and the ratios included in the ratio interval are all the ratios corresponding to the port group. The ratio intervals corresponding to different port groups may have an intersection or may not have an intersection. The signal-to-noise ratio corresponding to any port included in a port group is within the signal-to-noise ratio interval corresponding to the port group. For example, the signal-to-noise ratio interval corresponding to the port group can be determined based on the signal-to-noise ratios corresponding to some or all of the ports included in the port group. Similarly, the ratio of the channel gain to the cell noise floor corresponding to any port included in a port group is within the ratio interval corresponding to the port group. For example, the ratio interval corresponding to a port group can be determined based on the ratios corresponding to some or all ports included in a port group.

[0102] For example, refer to Table 2, which is an example of the mapping relationship. The mapping relationship, for example, includes one or more items in Table 2, where in Table 2, the index of a port group, an MCS interval, and a frequency domain density offset may constitute a set of mapping relationships. It can be seen that Table 2 includes multiple sets of mapping relationships, and the mapping relationship indicated by the first information, for example, includes some or all of the mapping relationships in the multiple sets of mapping relationships shown in Table 2.

[0103] Table 2

[0104] For example, in Table 2, each port group (or, each port group index) may correspond to multiple MCS intervals. Under each port group, each MCS interval in the multiple MCS intervals corresponds to a frequency domain density offset, wherein different MCS intervals correspond to the same or different frequency domain density offsets. This may be a property satisfied by any row in Table 2. For another example, in Table 2, each MCS interval may correspond to multiple port groups (or, correspond to multiple port group indexes). Under each MCS interval, each port group in the multiple port groups (or, each port group index) corresponds to a frequency domain density offset, wherein different port groups correspond to the same or different frequency domain density offsets. This may be a property satisfied by any column in Table 2.

[0105] Table 2 uses 12 port groups as an example. For port group #1, when the MCS value is in the range greater than or equal to 0 and less than or equal to 4, the corresponding frequency domain density offset is -2RE / 2RB. The understanding of other mapping relationships in Table 2 is similar. For example, in Table 2, the MCS intervals corresponding to port group #1 include MCS 0 to MCS 4, MCS 5 to MCS 10, MCS 11 to MCS 19, and MCS 20 to MCS 27. The frequency domain density offsets corresponding to port group #1 include -2RE / 2RB, -1RE / 2RB, 0, and +1RE / 2RB. Under port group #1, these frequency domain density offsets correspond one-to-one to the above MCS intervals. It can be seen that in the MCS intervals and frequency domain density offsets corresponding to port group #1, different MCS intervals correspond to different frequency domain density offsets. For another example, in Table 2, the port group indexes corresponding to MCS 0 to MCS 4 include 1 to 12, and the frequency domain density offsets corresponding to MCS 0 to MCS 4 include -2RE / 2RB, -1RE / 2RB, ..., 0. In the range of MCS 0 to MCS 4, these frequency domain density offsets correspond one-to-one with the port groups 1 to 12. It can be seen that among the port group indexes and frequency domain density offsets corresponding to MCS 0 to MCS 4, the frequency domain density offsets corresponding to different port group indexes may be the same or different (in the frequency domain density offsets not shown, some may have the same frequency domain density offset).

[0106] That is, the embodiment of the present application believes that MCS will be affected by the channel estimation performance, or it is understood that, under a given MCS, the channel estimation performance will affect the transmission success rate. Therefore, the embodiment of the present application can associate MCS with the frequency domain density (or frequency domain density offset) of the reference signal, so that a more appropriate frequency domain density can be determined by MCS. For example, referring to Figure 4A, it is a schematic diagram of the relationship between the frequency domain density of the reference signal and MCS under a given port. Figure 4A takes the reference signal as DMRS as an example. For example, for the receiving end of DMRS (UE or network equipment), channel estimation is performed based on the received DMRS, and the result of the channel estimation will be affected by parameters such as the DMRS input signal-to-noise ratio (SNR) and the frequency domain density of DMRS. After channel estimation, the receiving end performs MIMO equalization processing based on the channel estimation result and PDSCH, and the result of MIMO equalization will be affected by parameters such as the DMRS output SNR and pre-processing (pre) SINR. For example, if the SNR is poor, the MIMO equalization effect may be poor, resulting in a low SINR (signal to interference plus noise ratio) of the output post-processing signal, which will cause the MCS used when performing channel demodulation or decoding to be low. Inversely, it can be seen that the MCS is related to the frequency domain density of the DMRS. Therefore, the embodiment of the present application establishes an association between the MCS and the frequency domain density of the reference signal, so that the corresponding frequency domain density can be determined by the expected MCS to improve the channel estimation accuracy, thereby improving the performance of channel demodulation or decoding.

[0107] Please refer to Figure 4B again, which is a schematic diagram of the maximum MCS changing with the frequency domain density of the reference signal for a given port or a given port group. Figure 4B also takes the reference signal being DMRS as an example. In addition, the "stream" in Figure 4B can correspond to a port or a port group, for example, one stream corresponds to one port or one port group. The horizontal axis in Figure 4B represents the frequency domain density of the reference signal, and the vertical axis represents the MCS. According to Figure 4B, as the frequency domain density decreases, the MCS also gradually decreases. For example, for MCS 17 to MCS 25, the corresponding frequency domain density is approximately 1 / 12 to 1 / 60, that is, there is a certain amount of room for adjustment in the frequency domain density. If the MCS is less than or equal to 17, the corresponding frequency domain density is smaller. The simulation parameters in FIG4B include a clustered delay line (CDL)-A channel model, a multipath delay spread of 100 ns, a user speed of 3 km / h, EsN0 = 25 dB, a subcarrier spacing of 30 kHz, and 24 layers of single-user (SU)-MIMO. EsN0 represents noise and interference.

[0108] According to FIG. 4A and / or FIG. 4B , a mapping relationship between the MCS and the frequency domain density (or frequency domain density offset) of the reference signal can be obtained, for example, as follows: MCS = f(stream index or port index, frequency domain density of the reference signal corresponding to the port) (Formula 1)

[0109] Optionally, for a port, a larger MCS corresponding to the port increases the frequency domain density of the reference signal corresponding to the port, or a larger frequency domain density offset of the reference signal corresponding to the port increases; and / or, for a port, a smaller MCS corresponding to the port decreases the frequency domain density of the reference signal corresponding to the port, or a smaller frequency domain density offset of the reference signal corresponding to the port decreases. The port is, for example, a specific port among the N ports, or any one of the N ports. For example, for a port with a larger gain (e.g., a top port), if the SNR allows, the frequency domain density of the reference signal corresponding to the port can be appropriately reduced to save reference signal overhead. For another example, for a port with a smaller gain (e.g., a bottom port), if frequency domain resources allow, the frequency domain density corresponding to the port can be appropriately increased to improve the channel estimation accuracy of the port.

[0110] For example, see Table 3, which shows an example of the mapping relationship between frequency domain density and MCS. In Table 3, "flow" may correspond to a port or a port group. For example, "flow #1" may be replaced with "port #1" or "port group #1."

[0111] Table 3

[0112] For example, in Table 3, each stream (or each stream index) may correspond to multiple frequency domain densities. Under each stream, each of the multiple frequency domain densities corresponds to an MCS, where the MCSs corresponding to different frequency domain densities are the same or different. This property may be satisfied by any row in Table 3. For another example, in Table 3, each frequency domain density may correspond to multiple streams (or multiple stream indexes). Under each frequency domain density, each of the multiple streams (or each stream index) corresponds to an MCS, where the MCSs corresponding to different streams are the same or different. This property may be satisfied by any column in Table 3.

[0113] For example, in Table 3, when the frequency domain density of the reference signal is 1 / 12, the average MCS value of stream #1 is 22.0, the average MCS value of stream #5 is 18.5, and so on.

[0114] Optionally, in the mapping relationship indicated by the first information, the sum of the frequency domain density offsets of the reference signals corresponding to the M ports may be less than or equal to the first threshold, or the sum of the frequency domain density offsets of the reference signals corresponding to the N ports may be less than or equal to the first threshold; and / or, in the mapping relationship indicated by the first information, the sum of the frequency domain density offsets of the reference signals corresponding to at least one port group may be less than or equal to the first threshold, or the sum of the frequency domain density offsets of the reference signals corresponding to the port group in which the M ports are located may be less than or equal to the first threshold. The first threshold may be predefined by a protocol, or configured by a network device or UE, or preconfigured in the network device and UE, or the network device and UE may not perceive the first threshold. The first threshold is, for example, greater than or equal to 0. For example, the sum of the frequency domain density offsets of the reference signals corresponding to the N ports is 0, indicating that the overall overhead of the reference signal has not changed before and after the frequency domain density adjustment. When the reference signal overhead remains unchanged, the embodiment of the present application can improve the channel estimation accuracy.

[0115] Optionally, the difference between the first frequency domain density and the second frequency domain density may be less than or equal to the second threshold, or the absolute value of the difference between the first frequency domain density and the second frequency domain density may be less than or equal to the second threshold. The first frequency domain density is the sum of the frequency domain densities corresponding to the M ports determined according to the frequency domain density offset of the reference signals corresponding to the N ports, or the sum of the frequency domain densities corresponding to the M ports determined according to the frequency domain density offset of the reference signals corresponding to the M ports; the second frequency domain density is the sum of the initial frequency domain densities corresponding to the N ports, or the sum of the initial frequency domain densities corresponding to the M ports, or the second frequency domain density is the sum of the frequency domain densities corresponding to the M ports not determined according to the frequency domain density offset of the reference signals corresponding to the M ports, or the second frequency domain density is the sum of the frequency domain densities corresponding to the N ports not determined according to the frequency domain density offset of the reference signals corresponding to the N ports. It can be understood that the first frequency domain density is the frequency domain density after the M ports are adjusted, and the second frequency domain density is the frequency domain density before the M ports are adjusted; or, the first frequency domain density is the frequency domain density after the N ports are adjusted, and the second frequency domain density is the frequency domain density before the N ports are adjusted. The second threshold can be predefined by a protocol, or configured by a network device or a UE, or preconfigured in the network device and the UE, or the network device and the UE may not perceive the second threshold. The second threshold is, for example, greater than or equal to 0. For example, the difference between the first frequency domain density and the second frequency domain density is 0, indicating that the overall overhead of the reference signal has not changed before and after the frequency domain density is adjusted. When the reference signal overhead remains unchanged, the embodiment of the present application can improve the channel estimation accuracy.

[0116] For another example, if the first frequency domain density is smaller than the second frequency domain density, then after adjusting the frequency domain density of the reference signals corresponding to the M ports, the overall frequency domain density is reduced. Therefore, a portion of the resources originally used to send the reference signal (for example, called the first reference signal resource, which can be understood as the resource corresponding to the absolute value of the difference between the first frequency domain density and the second frequency domain density) is no longer used to send the reference signal. Then the UE can use the first reference signal resource to send or receive data to improve resource utilization. Optionally, in this case, the first frequency domain density is the sum of the frequency domain densities corresponding to the M ports determined according to the frequency domain density offset of the reference signals corresponding to the M ports, and the second frequency domain density is the sum of the frequency domain densities corresponding to the M ports that are not determined according to the frequency domain density offset of the reference signals corresponding to the M ports.

[0117] Regardless of whether the first information indicates the mapping relationship between different MCSs and the frequency domain density offsets of reference signals corresponding to different ports, or indicates the mapping relationship between different MCSs and the frequency domain density offsets of reference signals corresponding to different port groups, the first information can be considered as an implicit indication. After obtaining the first information, the UE needs to combine other information to determine the frequency domain density offset, or determine the final frequency domain density.

[0118] Optionally, the method may further include S303: the network device sends downlink control information (DCI), and accordingly, the UE receives the DCI from the network device. The DCI may indicate one or more MCSs, where the one or more MCSs correspond to M ports, for example, the DCI indicates an association between the indexes of the M ports and the one or more MCSs; or, the DCI may indicate M ports, where the M ports correspond to one or more MCSs, for example, the DCI indicates an association between the indexes of the M ports and the one or more MCSs. The number of the one or more MCSs may be less than or equal to M. For example, if the number of the one or more MCSs is equal to M, the one or more MCSs may correspond one-to-one with the M ports; or, if the number of the one or more MCSs is less than M, some of the one or more MCSs may correspond to multiple ports among the M ports, that is, multiple ports correspond to the same MCS. For example, the DCI may schedule PDSCHs corresponding to the M ports, and the PDSCHs of different ports may correspond to their respective MCSs, so that the DCI may indicate multiple MCSs corresponding to the PDSCHs corresponding to the M ports. The UE can determine the frequency domain density offset of the reference signal corresponding to some or all of the M ports based on the mapping relationship indicated by the first information and the one or more MCSs. For example, if the mapping relationship indicated by the first information is shown in Table 1 and the DCI indicates that the MCS of port #1 is MCS 2, the UE can determine that the frequency domain density offset of the reference signal corresponding to port #1 is -2RE / 2RB.

[0119] For example, if the first information is sent by the network device, one sending method is that the first information is included in the DCI, then S302 and S303 can be the same step; alternatively, even if the first information is sent by the network device, the first information may not be included in the DCI, but may be sent via other messages (such as radio resource control (RRC) messages or other DCI, etc.), then S302 and S303 are different steps. If S302 and S303 are different steps, then S303 may occur before S302, after S302, or simultaneously with S302.

[0120] Optionally, the network device may be an integrated architecture or a distributed architecture, for example, the network device includes a CU and / or a DU, or includes one or more of a CU-CP, a CU-UP, or a DU. When the network device includes a DU, the network device sends DCI to the UE, specifically, the DU included in the network device sends DCI to the UE. Optionally, the network device including the DU may further include a CU; or, the network device including the DU may further include a CU-CP and / or a CU-UP.

[0121] In addition to the implicit indication method described above, the first information may also be indicated in an explicit manner.

[0122] As another optional implementation of the first information, the first information may indicate a frequency domain density offset of a reference signal corresponding to each of the M ports, or the first information may indicate a frequency domain density offset of a reference signal corresponding to each port group in at least one port group. If the first information indicates a frequency domain density offset of a reference signal corresponding to a port group, then for all ports in a port group, the frequency domain density is adjusted using the frequency domain density offset corresponding to the port group.

[0123] The network device can determine the frequency domain density offset of the reference signal corresponding to each of the M ports. For example, the network device can determine the frequency domain density offset of the reference signal corresponding to each port based on the mapping relationship between the aforementioned different MCSs and the frequency domain density offsets of the reference signals corresponding to different ports, and then indicate the frequency domain density offset to the UE through the first information. Alternatively, the network device can determine the frequency domain density offset of the reference signal corresponding to each port group in at least one port group. For example, the network device can determine the frequency domain density offset of the reference signal corresponding to each port group based on the mapping relationship between the aforementioned different MCSs and the frequency domain density offsets of the reference signals corresponding to different port groups, and then indicate the frequency domain density offset to the UE through the first information. As a result, the UE no longer needs to perform the process of determining the frequency domain density offset based on the mapping relationship, which helps to simplify the implementation of the UE.

[0124] As another optional implementation of the first information, the first information may indicate the frequency domain density of the reference signal corresponding to each of the M ports, or the first information may indicate the frequency domain density of the reference signal corresponding to each port group in at least one port group. If the first information indicates the frequency domain density of the reference signal corresponding to a port group, the frequency domain density corresponding to the port group is used for all ports within the port group.

[0125] The network device can determine the frequency domain density offset of the reference signal corresponding to each of the M ports. For example, the network device can determine the frequency domain density offset of the reference signal corresponding to each port based on the mapping relationship between the aforementioned different MCSs and the frequency domain density offsets of the reference signals corresponding to different ports. In addition, the network device can determine the frequency domain density of the reference signal corresponding to each of the M ports based on the initial frequency domain density of the reference signal corresponding to the port and the frequency domain density offset of the reference signal corresponding to each port. The frequency domain density is the result of adjusting the initial frequency domain density according to the frequency domain density offset. The network device then indicates the frequency domain density offset to the UE through the first information. Alternatively, the network device may determine a frequency domain density offset for a reference signal corresponding to each port group in at least one port group. For example, the network device may determine the frequency domain density offset for the reference signal corresponding to each port group based on the aforementioned mapping relationship between different MCSs and the frequency domain density offsets for the reference signals corresponding to different port groups. Furthermore, the network device may determine the frequency domain density for the reference signal corresponding to each port group in at least one port group based on the initial frequency domain density for the reference signal and the frequency domain density offset for the reference signal corresponding to each port group, and then indicate the frequency domain density offset to the UE via first information. The initial frequency domain density for the reference signal corresponding to a port group may be the frequency domain density for the reference signal corresponding to any port in the port group. For example, the frequency domain densities for the reference signals corresponding to the M ports are all equal, i.e., the initial frequency domain densities corresponding to different ports in the M ports may all be equal. Through the first information, the UE no longer needs to perform the process of determining the frequency domain density offset based on the mapping relationship, and even does not need to perceive the frequency domain density offset. Instead, the UE can directly obtain the final frequency domain density, which helps simplify UE implementation.

[0126] When the first information adopts the explicit indication manner as described above, optionally, the method may also include the aforementioned S303.

[0127] Optionally, if the first information is sent by the network device to the UE, and the UE sends capability information to the network device, the network device may determine the first information in combination with the capability information of the UE. For example, if the capability information of the UE indicates that the UE does not support adjusting the frequency domain density for M ports, the network device may not need to send the first information to the UE, and the UE does not need to adjust the frequency domain density, but directly apply the initial frequency domain density of the reference signal corresponding to the M ports. For another example, if the capability information of the UE indicates that the UE does not support adjusting the frequency domain density for some of the M ports, the first information sent by the network device may not indicate the frequency domain density offset for these ports that do not support adjusting the frequency domain density, or the indicated frequency domain density offset may be 0. For another example, if the capability information of the UE indicates the maximum value and / or minimum value of the frequency domain density offset of the reference signal corresponding to a certain port of the UE, the frequency domain density offset of the reference signal corresponding to the port determined according to the first information sent by the network device may be less than or equal to the maximum value, and / or greater than or equal to the minimum value.

[0128] S304. The UE determines the frequency domain density of the reference signals corresponding to the M ports according to the frequency domain density offsets of the reference signals corresponding to the M ports.

[0129] For example, the UE determines the frequency domain density of the reference signal corresponding to each of the M ports based on the frequency domain density offset of the reference signal corresponding to each port in the M ports. Alternatively, the UE determines the frequency domain density of the reference signal corresponding to each port group in at least one port group based on the frequency domain density offset of the reference signal corresponding to each port group in at least one port group.

[0130] Optionally, the first information, for example, indicates a mapping relationship between different MCSs and frequency domain density biases of reference signals corresponding to different ports, or indicates a mapping relationship between different MCSs and frequency domain density biases of reference signals corresponding to different port groups, or indicates a frequency domain density bias corresponding to each of the M ports. The UE can determine the frequency domain density of the reference signals corresponding to the M ports based on the frequency domain density bias of the reference signals corresponding to each of the M ports and the initial frequency domain density of the reference signals corresponding to each of the M ports.

[0131] For example, the DCI in S303 also indicates a DMRS pattern, and the UE can determine the initial frequency domain density of the reference signal corresponding to each of the M ports based on the DMRS pattern. Alternatively, the DCI does not indicate a DMRS pattern, and the UE can determine the initial frequency domain density of the reference signal corresponding to each of the M ports based on other information, for example, the other information includes one or more of the following: a default value of the frequency domain density of the reference signal corresponding to each of the M ports predefined by the protocol, an initial frequency domain density of the reference signal corresponding to each of the M ports preconfigured in the UE and the network device, or a frequency domain density of the reference signal corresponding to each of the M ports configured by high-level signaling from the network device (such as RRC layer signaling or signaling from other protocol layers). Alternatively, the DCI does not indicate a DMRS pattern, and the UE cannot determine the initial frequency domain density of the reference signal corresponding to each of the M ports based on other information, then the UE does not need to adjust the frequency domain density of the M ports. For example, refer to Table 4, which is an example of the initial frequency domain density of the reference signal corresponding to the port.

[0132] Table 4

[0133] Table 4 uses 24 ports as an example. In Table 4, the initial frequency domain density of each port is 1 RE / 1 RB. For example, M ports include some or all of the ports shown in Table 4. Assuming that the first information is Table 1 and the initial frequency domain density of the reference signals corresponding to the M ports is Table 4, the frequency domain density of the reference signals corresponding to the M ports determined by the UE can be referred to in Table 5.

[0134] Table 5

[0135] As described above, if the first information indicates, for example, a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different ports, or indicates a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, or indicates the frequency domain density offset corresponding to each of the M ports, the UE may execute S304. Alternatively, if the first information indicates the frequency domain density of the reference signal corresponding to each of the M ports, which is equivalent to the first information directly indicating the adjusted frequency domain density, the UE may not need to execute S304, that is, the UE can determine the frequency domain density of the reference signal corresponding to each of the M ports by obtaining the first information.

[0136] S305: The network device determines the frequency domain density of the reference signals corresponding to the M ports according to the frequency domain density offsets of the reference signals corresponding to the M ports.

[0137] For example, if the first information is predefined by a protocol or preconfigured in a network device, the network device may determine the frequency domain density offsets of the reference signals corresponding to the M ports based on the first information, and determine the frequency domain densities of the reference signals corresponding to the M ports based on the frequency domain density offsets of the reference signals corresponding to the M ports; alternatively, the network device may directly determine the frequency domain densities of the reference signals corresponding to the M ports based on the first information (thereby eliminating the need to execute S305). For the above determination method, reference may be made to the description of the UE's determination process described above.

[0138] Alternatively, if the first information is sent by the network device to the UE, the network device may first determine the frequency domain density offsets of the reference signals corresponding to the M ports, and determine the frequency domain density of the reference signals corresponding to the M ports based on the frequency domain density offsets of the reference signals corresponding to the M ports. For example, the network device first obtains a mapping relationship (a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different ports, or a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups), for example, the network device generates the mapping relationship by itself, or the mapping relationship is preconfigured in the network device. After obtaining the mapping relationship, the network device can determine the frequency domain density offset of the reference signal corresponding to each of the M ports based on the mapping relationship. For example, the network device can determine the frequency domain density offset of the reference signal corresponding to each of the M ports in combination with the multiple MCSs described above (i.e., one or more MCSs indicated by the DCI), and determine the frequency domain density of the reference signal corresponding to each of the M ports based on the frequency domain density offset of the reference signal corresponding to each of the M ports. The determination method can refer to the introduction to the determination process of the UE in S304. The first information sent by the network device to the UE can directly indicate the mapping relationship, or indicate the frequency domain density offset or frequency domain density of the reference signal corresponding to each of the M ports.

[0139] S306. The UE sends a reference signal according to the frequency domain density of the reference signals corresponding to the M ports, and accordingly, the network device receives the reference signal according to the frequency domain density of the reference signals corresponding to the M ports. Alternatively, the network device sends a reference signal according to the frequency domain density of the reference signals corresponding to the M ports, and accordingly, the UE receives the reference signal according to the frequency domain density of the reference signals corresponding to the M ports.

[0140] Optionally, the network device may be an integrated architecture or a distributed architecture, for example, the network device includes a CU and / or a DU, or includes one or more of a CU-CP, a CU-UP, or a DU. When the network device includes a DU, the network device receives a reference signal from the UE, specifically, the DU included in the network device receives a reference signal from the UE; similarly, when the network device includes a DU, the network device sends a reference signal to the UE, specifically, the DU included in the network device sends a reference signal to the UE. Optionally, the network device including the DU may further include a CU; or, the network device including the DU may further include a CU-CP and / or a CU-UP.

[0141] Among them, the reference signal must be sent and received between the UE and the network device according to the frequency domain density of the reference signal corresponding to the M ports, and the frequency domain resource position mapped to the reference signal corresponding to each of the M ports must also be determined. It can be understood that the embodiment of the present application adjusts the frequency domain density of the reference signal corresponding to the port, so for a port, the frequency domain resource position mapped to the reference signal sent or received through the port may also change. Therefore, the UE and the network device can determine the frequency domain resource position mapped to the reference signal sent or received through the port, so that the reference signal can be sent or received through the port.

[0142] Optionally, the second information may indicate the frequency domain resource location mapped to the reference signal corresponding to each of the M ports. For example, if the second information is predefined by the protocol, both the UE and the network device may determine the frequency domain resource location mapped to the reference signal corresponding to each of the M ports based on the second information predefined by the protocol; or, if the second information is sent by the network device to the UE, the network device may determine the frequency domain resource location mapped to the reference signal corresponding to each of the M ports, and then indicate it to the UE through the second information. The second information and the aforementioned first information may be the same information, or the two may be different information.

[0143] Alternatively, the frequency domain resource location to which the reference signal corresponding to each of the M ports is mapped is predefined. For example, for each possible frequency domain density, the protocol may predefine the frequency domain resource location to which the reference signal is mapped under that frequency domain density. Thus, once the UE or network device determines the frequency domain density of the reference signal corresponding to a particular port, it can determine the frequency domain resource location to which the reference signal corresponding to that port is mapped according to the protocol.

[0144] For example, referring to Figures 5A and 5B, Figure 5A shows the frequency domain resource positions to which the reference signals are mapped when the frequency domain density of the reference signals corresponding to the M ports is the initial frequency domain density, and Figure 5B shows the frequency domain resource positions to which the reference signals are mapped when the frequency domain density of the reference signals corresponding to the M ports is the adjusted frequency domain density. Figures 5A and 5B take M=24 as an example, where the horizontal axis represents time, the vertical axis represents frequency, and each vertical box represents a subcarrier. In Figures 5A and 5B, the shaded boxes represent the frequency domain resource positions to which the reference signals are mapped. For example, in Figure 5A, the frequency domain resources to which the reference signals are mapped for each port from port 1 to port 24 are subcarriers 0, 12, 24, etc. In Figure 5B, the frequency domain resources to which the reference signals are mapped for each port, such as port 1 and port 2, are subcarriers 0, 24, etc., and the frequency domain resources to which the reference signals are mapped for port 24 are subcarriers 0, 6, 12, 18, 24, etc.

[0145] After determining the frequency domain resource position to which the reference signal corresponding to each of the M ports is mapped, the UE and the network device can transmit and receive the reference signal at the frequency domain resource position to which the reference signal corresponding to each of the M ports is mapped.

[0146] Optionally, the method may further include S307, where the reference signal receiving end performs channel estimation based on the received reference signal. For example, if the reference signal is a DMRS, the reference signal receiving end may perform channel estimation based on the DMRS. The reference signal receiving end may be, for example, a UE or a network device. FIG3 takes a UE as an example.

[0147] For example, the UE may use a Wiener filter to perform channel estimation, or the UE may use other methods to perform channel estimation, without limitation. The following uses the Wiener filter as an example to introduce the UE's channel estimation process.

[0148] After receiving the DMRS, the UE can determine the information of the downlink channel based on the DMRS, and process the downlink channel information through a Wiener filter to obtain a channel estimation result. The channel estimation result can represent the channel information on the resources that do not carry the DMRS, for example, the PDSCH information, which is, for example, the PDSCH scheduled by the DCI described in S302.

[0149] For example, W can be obtained by using the Wiener filter d , according to W d The channel estimation result can be obtained. d Can represent a port group. d For example, the following relationship is satisfied:

[0150] In formula 2, Represents the covariance matrix of the channel matrix at the time-frequency resource position where the reference signal is located, I p Represents The SNR represents the estimated value of the signal-to-noise ratio corresponding to the downlink channel. In addition, in formula 2, For example, the following relationship is satisfied:

[0151] In formula 3 Compared with the formula 2 is the same parameter, where n represents the nth subcarrier or frequency domain position, and m represents the mth subcarrier or frequency domain position. or Represents the filter coefficient of the Wiener filter.

[0152] In formula 3 represents the time-delay frequency domain autocorrelation function, The following relationship can be satisfied:

[0153] Here, FFT stands for fast Fourier transform (FFT).

[0154] R in Formula 4 p (τ) represents the delay domain power spectrum, R p (τ) can satisfy the following relationship:

[0155] In formula 5, τ RMS represents the root mean square (RMS) of the multipath delay τ, τ represents the multipath delay, Δ m Indicates timing deviation, Δ max Indicates the maximum value of multipath delay deviation,

[0156] Please refer to Figure 6, which is a schematic diagram of the relationship between the interpolation filtering performance of the Wiener filter and the frequency domain density of the reference signal. The horizontal axis of Figure 6 represents the delay and the vertical axis represents the power. According to Figure 6, the frequency domain density of the reference signal will affect the length of the sampling time (or called the sampling width, that is, the delay domain sampling width of the filter at the receiving end (such as UE)). For example, the length of the sampling time is proportional to the inverse of the frequency domain density of the reference signal. The greater the frequency domain density, the greater the sampling time, and the more signals are sampled. If the effective part of the signal can be collected within the sampling time (such as the peak area shown in Figure 6), the channel estimation result obtained will be better; but if the sampling time is short, the effective part of the signal may not be collected or cannot be fully collected, which is equivalent to losing part of the signal, and the channel estimation result will be relatively poor. The embodiment of the present application can adjust the frequency domain density of the reference signal corresponding to the port, so as to maximize the interpolation filtering performance of the Wiener filter.

[0157] The embodiment of the present application can determine the frequency domain density offset of the reference signals corresponding to the M ports based on the first information. For example, the frequency domain density offsets of the reference signals corresponding to different ports are the same or different, thereby being able to adjust the frequency domain density for the reference signals corresponding to different ports separately, and the adjustment granularity is finer. The frequency domain density offset can be determined based on the MCS, which is equivalent to reflecting the requirements for the channel, or reflecting the channel conditions, so that the frequency domain density of the reference signal corresponding to each port can be consistent with factors such as the channel conditions of the port. When performing channel estimation based on DMRS, channel estimation can be performed based on the frequency domain density of the reference signal corresponding to the corresponding port. This is equivalent to the channel estimation process taking into account the channel conditions corresponding to the port, so that the channel estimation process can adapt to various different channel conditions, which helps to improve the accuracy of channel estimation.

[0158] FIG7 shows a schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device 700 may be the UE or the circuit system of the UE described in the embodiment shown in FIG3 , and is used to implement the method corresponding to the UE in the above method embodiment. Alternatively, the communication device 700 may be the network device or the circuit system of the network device described in the embodiment shown in FIG3 , and is used to implement the method corresponding to the network device in the above method embodiment. For example, one circuit system is a chip system.

[0159] The communication device 700 includes at least one processor 701. Processor 701 can be used for internal processing of the device to implement certain control processing functions. Optionally, processor 701 includes instructions. Optionally, processor 701 can store data. Optionally, different processors can be independent devices, located in different physical locations, or on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, on one or more integrated circuits.

[0160] Optionally, the communication device 700 includes one or more memories 703 for storing instructions. Optionally, data may also be stored in the memories 703. The processor and memory may be provided separately or integrated together.

[0161] Optionally, communication device 700 includes a communication circuit 702 and at least one communication interface 704. Memory 703, communication circuit 702, and communication interface 704 are optional and are therefore represented by dashed lines in FIG7 . Communication interface 704 may include an input interface and / or an output interface; alternatively, communication interface 704 may include a transceiver capable of transmitting and / or receiving functions.

[0162] Optionally, the communication device 700 may further include a transceiver and / or an antenna. The transceiver may be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver, a transceiver circuit, an input / output interface, etc., and is used to implement the transceiver function of the communication device 700 via an antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter may be used to generate a radio frequency signal from a baseband signal, and the receiver may be used to convert the radio frequency signal into a baseband signal.

[0163] The processor 701 may include a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0164] Communication link 702 may include a pathway for transmitting information between the aforementioned components.

[0165] The communication interface 704 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0166] The memory 703 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 703 may exist independently and be connected to the processor 701 via the communication line 702. Alternatively, the memory 703 may be integrated with the processor 701.

[0167] The memory 703 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 701. The processor 701 is used to execute the computer-executable instructions stored in the memory 703, thereby implementing the steps performed by the UE or network device in the embodiment shown in Figure 3.

[0168] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0169] In a specific implementation, as an embodiment, the processor 701 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 7 .

[0170] In a specific implementation, as an embodiment, the communication device 700 may include multiple processors, such as the processor 701 and the processor 705 in FIG7 . Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0171] When the device shown in FIG7 is a chip, such as a chip of a UE or a chip of a network device, the chip includes a processor 701 (and may also include a processor 705), a communication circuit 702, and a communication interface 704. Optionally, the chip may include a memory 703. Specifically, the communication interface 704 may be an input interface, a pin, or a circuit. The memory 703 may be a register, a cache, or the like. The processor 701 and the processor 705 may be a general-purpose CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the communication method of any of the above embodiments.

[0172] In the embodiment of the present application, the functional modules of the device can be divided according to the above-mentioned method examples. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation. For example, in the case of dividing each functional module according to each function, Figure 8 shows a schematic diagram of a device. The device 800 can be the UE or network device involved in the above-mentioned method embodiments, or a chip in the UE or a chip in the network device. The device 800 includes a transceiver unit and a processing unit 802. The transceiver unit can be used to perform all sending steps and / or all receiving steps performed by the UE or network device in the above-mentioned method embodiments; the processing unit 802 can be used to perform all or part of the remaining steps performed by the UE or network device in the above-mentioned method embodiments except the sending and receiving steps. Optionally, the transceiver unit may be a whole, capable of realizing the sending function and / or the receiving function; or, the transceiver unit may include a sending unit 801 and / or a receiving unit 803, the sending unit 801 is used to realize the sending function, and the receiving unit 802 is used to realize the receiving function.

[0173] It should be understood that the device 800 can be used to implement the steps performed by the UE or network device in the communication method of the embodiment of the present application. The relevant features can refer to the embodiment shown in Figure 3 above and will not be repeated here.

[0174] Optionally, the functions / implementation processes of the sending unit 801, the receiving unit 803, and the processing unit 802 in FIG8 may be implemented by the processor 701 in FIG7 calling computer-executable instructions stored in the memory 703. Alternatively, the functions / implementation processes of the processing unit 802 in FIG8 may be implemented by the processor 701 in FIG7 calling computer-executable instructions stored in the memory 703, and the functions / implementation processes of the sending unit 801 and the receiving unit 803 in FIG8 may be implemented by the communication interface 704 in FIG7.

[0175] Optionally, when the device 800 is a chip or a circuit, the functions / implementation processes of the sending unit 801 and the receiving unit 803 can also be implemented through pins or circuits.

[0176] The present application also provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed, the method performed by the UE or network device in the aforementioned method embodiment is implemented. In this way, the functions described in the above embodiments can be implemented in the form of software functional units and sold or used as independent products. Based on this understanding, the technical solution of the present application can be essentially or in other words, the part that contributes or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. Storage media include various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0177] The present application also provides a computer program product, which includes: computer program code, which, when running on a computer, enables the computer to execute the method executed by the UE or the network device in any of the aforementioned method embodiments.

[0178] An embodiment of the present application further provides a processing device, including a processor and an interface; the processor is used to execute the method executed by the UE or network device involved in any of the above method embodiments.

[0179] In the above embodiments, it 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. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. 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 can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0180] The various illustrative logic units and circuits described in the embodiments of the present application can be implemented or operated by a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

[0181] The steps of the methods or algorithms described in the embodiments of the present application can be directly embedded in hardware, software units executed by a processor, or a combination of the two. The software unit can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or other storage media in any form known in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and storage medium can be provided in an ASIC, which can be provided in a terminal device. Alternatively, the processor and storage medium can also be provided in different components in the terminal device.

[0182] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0183] The contents of the various embodiments of this application can refer to each other. If there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0184] It is understood that in the embodiments of the present application, the UE and / or the network device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples. In the embodiments of the present application, other operations or variations of various operations may also be performed. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application need to be performed.

Claims

1. A communication method, characterized in that: The method comprises: Acquire first information, where the first information is used to determine a frequency domain density offset of a reference signal corresponding to M ports, where M is a positive integer; Determining the frequency domain density of the reference signals corresponding to the M ports according to the frequency domain density offsets of the reference signals corresponding to the M ports; The reference signal is sent or received according to the frequency domain density of the reference signal corresponding to the M ports.

2. The method according to claim 1, characterized in that: Obtain the first information, including: receiving first information from a network device; or, The predefined first information is obtained.

3. The method according to claim 1 or 2, characterized in that: The first information is used to indicate a mapping relationship between different modulation and coding strategies MCS and frequency domain density offsets of reference signals corresponding to different ports.

4. The method according to claim 3, characterized in that The mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and indexes of N ports, wherein the index of each port in the N ports corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port in the N ports, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port indexes are the same or different; The N ports include the M ports.

5. The method according to claim 1 or 2, characterized in that: The first information is used to indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, wherein one port group includes one or more ports among the M ports.

6. The method according to claim 5, characterized in that The mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and an index of at least one port group, wherein the index of each port group in the at least one port group corresponds to the at least one MCS interval, and among the MCS intervals and the frequency domain density offsets corresponding to one port group in the at least one port group, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port group indexes and the frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port group indexes are the same or different; The at least one port group includes N ports, and the N ports include the M ports.

7. The method according to any one of claims 3 to 6, characterized in that: For the same port among N ports, The larger the MCS corresponding to the port, the larger the frequency domain density offset of the reference signal corresponding to the port; or, The smaller the MCS corresponding to the port is, the smaller the frequency domain density offset of the reference signal corresponding to the port is; The N ports include the M ports.

8. The method according to any one of claims 3 to 7, characterized in that: A sum of frequency domain density offsets of reference signals corresponding to N ports is less than or equal to a first threshold, wherein the N ports include the M ports.

9. The method according to any one of claims 3 to 8, characterized in that: The method further comprises: receiving downlink control information from the network device, where the downlink control information is used to indicate one or more MCSs, where the one or more MCSs correspond to the M ports; According to the one or more MCSs and the mapping relationship indicated by the first information, a frequency domain density offset of a reference signal corresponding to some or all of the M ports is determined.

10. The method according to claim 1 or 2, characterized in that: The first information is used to indicate a frequency domain density offset of a reference signal corresponding to each of the M ports.

11. The method according to any one of claims 1 to 10, characterized in that: The first information is further used to indicate a frequency domain resource position to which a reference signal corresponding to each port of the M ports is mapped; or, The frequency domain resource position to which the reference signal corresponding to each port of the M ports is mapped is predefined.

12. The method according to any one of claims 1 to 11, characterized in that: The method further comprises: Sending capability information of the terminal device to the network device, the capability information being used to indicate whether the terminal device supports adjusting the frequency domain density of the M ports, or the capability information being used to indicate the frequency domain density supported by each of the M ports The maximum and minimum values ​​of the offset.

13. The method according to any one of claims 1 to 12, characterized in that: The difference between the first frequency domain density and the second frequency domain density is less than or equal to a second threshold, wherein the first frequency domain density is the sum of the frequency domain densities corresponding to the N ports determined according to the frequency domain density offset of the reference signals corresponding to the N ports, and the second frequency domain density is the sum of the initial frequency domain densities corresponding to the N ports, and the N ports include the M ports.

14. The method according to claim 13, characterized in that When the first frequency domain density is less than the second frequency domain density, the method further includes: Data is sent or received through a first reference signal resource, wherein the first reference signal resource is a reference signal resource corresponding to a difference between the second frequency domain density and the first frequency domain density.

15. A communication method, characterized in that: The method comprises: Determine the frequency domain density of the reference signals corresponding to the M ports according to the frequency domain density offsets of the reference signals corresponding to the M ports, where M is a positive integer; The reference signal is received or sent according to the frequency domain density of the reference signal corresponding to the M ports.

16. The method according to claim 15, characterized in that The method further comprises: Acquire the predefined first information; or, Sending first information to a terminal device, where the first information is used to determine a frequency domain density offset of a reference signal corresponding to the M ports.

17. The method according to claim 15 or 16, characterized in that The first information is used to indicate a mapping relationship between the different MCSs and frequency domain density offsets of reference signals corresponding to different ports.

18. The method according to claim 17, characterized in that The mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and indexes of N ports, wherein the index of each port in the N ports corresponds to the at least one MCS interval, and among the MCS intervals and frequency domain density offsets corresponding to one port in the N ports, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port indexes and frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port indexes are the same or different; The N ports include the M ports.

19. The method according to claim 15 or 16, characterized in that The first information is used to indicate a mapping relationship between different MCSs and frequency domain density offsets of reference signals corresponding to different port groups, wherein one port group includes one or more ports among the M ports.

20. The method according to claim 19, characterized in that The mapping relationship includes a mapping relationship between at least one MCS interval, at least one frequency domain density offset, and an index of at least one port group, wherein the index of each port group in the at least one port group corresponds to the at least one MCS interval, and among the MCS intervals and the frequency domain density offsets corresponding to one port group in the at least one port group, the frequency domain density offsets corresponding to different MCS intervals are the same or different, and among the port group indexes and the frequency domain density offsets corresponding to one MCS interval in the at least one MCS interval, the frequency domain density offsets corresponding to different port group indexes are the same or different; The at least one port group includes N ports, and the N ports include the M ports.

21. The method according to any one of claims 17 to 20, characterized in that: For the same port among N ports, The larger the MCS corresponding to the port, the larger the frequency domain density offset of the reference signal corresponding to the port; or, The smaller the MCS corresponding to the port is, the smaller the frequency domain density offset of the reference signal corresponding to the port is; The N ports include the M ports.

22. The method according to any one of claims 17 to 21, characterized in that: A sum of frequency domain density offsets of reference signals corresponding to N ports is less than a first threshold, wherein the N ports include the M ports.

23. The method according to any one of claims 17 to 22, characterized in that: The method further comprises: Send downlink control information to the terminal device, wherein the downlink control information is used to indicate one or more MCSs, and the one or more MCSs correspond to the M ports, wherein the one or more MCSs and the mapping relationship indicated by the first information are used to determine the frequency domain density offset of the reference signal corresponding to some or all of the M ports.

24. The method according to claim 15 or 16, characterized in that The first information is used to indicate a frequency domain density offset of a reference signal corresponding to each of the M ports.

25. The method according to any one of claims 15 to 24, characterized in that: The first information is further used to indicate a frequency domain resource position to which a reference signal corresponding to each port of the M ports is mapped; or, The frequency domain resource position to which the reference signal corresponding to each port of the M ports is mapped is predefined.

26. The method according to any one of claims 15 to 25, characterized in that: The method further comprises: Receive capability information from the terminal device, where the capability information is used to indicate whether the terminal device supports adjusting the frequency domain density of the M ports, or the capability information is used to indicate the maximum and minimum values ​​of the frequency domain density offset supported by each of the M ports.

27. The method according to any one of claims 15 to 26, characterized in that: The difference between the first frequency domain density and the second frequency domain density is less than a second threshold, wherein the first frequency domain density is the sum of the frequency domain densities corresponding to the M ports determined according to the frequency domain density offset of the reference signals corresponding to the M ports, and the second frequency domain density is the sum of the initial frequency domain densities corresponding to the M ports.

28. The method according to claim 27, characterized in that When the first frequency domain density is less than the second frequency domain density, the method further includes: Data is received or sent through a first reference signal resource, wherein the first reference signal resource is a reference signal resource corresponding to a difference between the second frequency domain density and the first frequency domain density.

29. A communication device, characterized in that: The communication device comprises a processing unit and a transceiver unit, wherein the processing unit is coupled to the transceiver unit to execute the method according to any one of claims 1 to 14, or execute the method according to any one of claims 15 to 28.

30. A communication device, characterized in that: The communication device comprises a processor, and the processor is configured to execute a computer program so that the communication device executes the method according to any one of claims 1 to 14, or the communication device executes the method according to any one of claims 15 to 28.

31. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and when the computer program is run on a computer, the computer is caused to execute the method according to any one of claims 1 to 14, or the computer is caused to execute the method according to any one of claims 15 to 28.

32. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is run on a computer, the computer is caused to execute the method according to any one of claims 1 to 14, or the computer is caused to execute the method according to any one of claims 15 to 28.

33. A chip system, characterized in that: The chip system comprises: A processor and an interface, wherein the processor is used to call and run instructions from the interface, and when the processor executes the instructions, the method according to any one of claims 1 to 14 is implemented, or the method according to any one of claims 15 to 28 is implemented.

34. A communication system, characterized in that: The communication system includes a terminal device and a network device, wherein: The terminal device is used to execute the method according to any one of claims 1 to 14; or, The network device is used to execute the method according to any one of claims 15 to 28.

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