WO2025223118A1 - Communication method and apparatus - Google Patents

Abstract

The present application relates to the technical field of communications, and provides a communication method and apparatus. The method comprises: receiving a first reference signal; determining a first precoding matrix on the basis of the first reference signal; sending a second reference signal, wherein the second reference signal is processed by means of the first precoding matrix, and the second reference signal is used for estimating a first amplitude of a first channel; and receiving first information on the first channel, the first information indicating the first amplitude. By means of the descried solution, the reference signal used for channel amplitude estimation may be processed by means of the precoding matrix. In this way, the reference signal has higher transmission quality, so that the receiving end can perform more accurate channel estimation on the basis of the high-quality transmitted reference signal.

Description

Communication methods and devices

This application claims priority to Chinese Patent Application No. 202410518474.9, filed on April 26, 2024, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of communication technology, and more specifically, to a communication method and apparatus.

Background Technology

Before a signal is transmitted from a physical antenna, it can be preprocessed. Preprocessing can alter the amplitude or phase of the signal after it is finally modulated onto a carrier. This can potentially eliminate channel-to-channel correlation, thereby enhancing channel independence between antenna ports, and enabling substream data mapped to each antenna port to be transmitted in a nearly uncorrelated manner over the spatial channel. In digital links, digital beamforming can be implemented through precoding.

When the channel quality is poor, terminal devices or network devices may have difficulty accurately estimating the channel, thus making it impossible to apply appropriate precoding to process the data to be transmitted, and making it difficult to guarantee the data transmission performance.

Therefore, how to accurately estimate the channel is an urgent problem to be solved.

Summary of the Invention

To address the aforementioned technical problems, this application provides a communication method and apparatus capable of accurately estimating the channel.

Firstly, a communication method is provided. The method provided in the first aspect can be executed by a first device. Unless otherwise specified, the first device in this application can refer to the first device itself (e.g., a network device or a terminal device), a component within the first device (e.g., a processor, a chip, or a chip system), or a logic module or software capable of implementing all or part of the functions of the first device. For ease of description, the following description uses a first device as an example.

The method includes: receiving a first reference signal; determining a first precoding matrix based on the first reference signal; transmitting a second reference signal processed by the first precoding matrix, the second reference signal being used to estimate a first amplitude of a first channel; and receiving first information on the first channel, the first information indicating the first amplitude.

The above scheme allows the reference signal used to estimate the channel amplitude to be processed by a precoding matrix. This results in higher transmission quality for the reference signal; for example, the beam of the reference signal can be aligned with the receiver. This scheme enables the receiver to perform more accurate channel estimation based on the high-quality transmitted reference signal. Those skilled in the art will understand that accurate channel parameters improve data transmission performance. Therefore, the above scheme supports improved data transmission performance.

In some implementations, determining the first precoding matrix based on the first reference signal includes: estimating the first Doppler frequency of the first channel based on the first reference signal, the first channel including a first path, the first Doppler frequency being the Doppler frequency of the first path; and determining the first precoding matrix based on the first Doppler frequency.

Through the above scheme, the first and second devices can jointly perform channel estimation. The first device estimates some parameters, such as the Doppler frequency, using a first reference signal. The second device estimates other parameters, such as the amplitude, using a second reference signal. Compared to a single-end channel estimation scheme, the above scheme enables dual-end channel estimation, thereby achieving more accurate channel estimation.

In some implementations, determining the first precoding matrix based on the first reference signal includes: estimating a first Doppler frequency and a second Doppler frequency of the first channel based on the first reference signal, the first channel including a first path and a second path, the first Doppler frequency being the Doppler frequency of the first path, and the second Doppler frequency being the Doppler frequency of the second path; and determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency.

In some implementations, before determining the first precoding matrix based on the first Doppler frequency, the method includes: obtaining first angular delay domain information of the first path based on the first reference signal; determining the first precoding matrix based on the first Doppler frequency includes: determining the first precoding matrix based on the first Doppler frequency and the first angular delay domain information.

Through the above scheme, the first device can determine the precoding matrix based on the Doppler frequency and angle delay domain information, thus improving the precoding processing effect. In this way, the energy of the reference signal on the path of the amplitude to be estimated is further concentrated, allowing the receiver to perform more accurate channel estimation based on the reference signal.

In some implementations, before determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency, the method includes: obtaining first angular delay domain information of the first path and second angular delay domain information of the second path based on the first reference signal; determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency includes: determining the first precoding matrix based on the first Doppler frequency, the first angular delay domain information, the second Doppler frequency, and the second angular delay domain information.

In some implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second matrix indicates the first angular delay domain information.

In some implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second Doppler frequency, and the second matrix indicates the first angular delay domain information and the second angular delay domain information.

In some implementations, the first channel comprises S paths, where S is a positive integer greater than or equal to 1, and the first precoding matrix F satisfies:

F = ( D T) -1 (E T ) -1 ;

D＝[d ₁ ,…,d _i ,…,d _S ];

Where i and j are integers, 1≤i≤S, 1≤j≤S; (E ^T ) ^-1 is the first matrix, e _j is the first Doppler frequency; (D ^T ) ^-1 is the second matrix, d _i is the first angular time delay domain information; "T" indicates matrix transpose, and "-1" indicates matrix inversion.

Based on the above scheme, the first precoding matrix can eliminate the influence of other parameter variables of the second reference signal in the first channel, enabling the second device to better estimate the amplitude of the first channel.

In some implementations, the first information includes a first identifier and a first amplitude, wherein the first amplitude is the amplitude of a first path and the first path is the path corresponding to the first identifier.

The above scheme allows the first information to include a path identifier, enabling the receiver to determine which path corresponds to the first amplitude. While reducing transmission overhead, this scheme accurately indicates the path corresponding to the amplitude.

In some implementations, the first information includes a second identifier and a second amplitude, wherein the second amplitude is the amplitude of a second path and the second path is the path corresponding to the second identifier.

In some implementations, the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path.

The above scheme allows the first information to include the path identifier and the amplitude index, enabling the receiver to determine the amplitude using the amplitude index and to identify which path the amplitude belongs to using the path identifier. While further reducing transmission overhead, this scheme accurately indicates the amplitude and the corresponding path.

In some implementations, the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path.

In some implementations, the first information indicates the first amplitude, including: the first information indicates the first amplitude and the second amplitude of the first channel.

In some implementations, after receiving first information on the first channel, the method includes: transmitting first data, which has been processed by a second precoding matrix determined based on the first amplitude and the second amplitude.

In some implementations, after receiving first information on the first channel, the method includes: transmitting first data, which has been processed by a second precoding matrix determined based on the first amplitude.

In some implementations, the first reference signal includes a sounding reference signal (SRS), and the second reference signal includes a channel state information reference signal (CSI-RS).

Secondly, a communication method is provided. The method provided in this application can be executed by a second device. Unless otherwise specified, the second device in this application can refer to the second device itself (e.g., a terminal device), a component within the second device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the second device. For ease of description, the following description uses a second device as an example.

The method includes: transmitting a first reference signal for determining a first precoding matrix; receiving a second reference signal processed by the first precoding matrix; estimating a first amplitude of a first channel based on the second reference signal; and transmitting first information on the first channel, the first information indicating the first amplitude.

In some implementations, the first reference signal is used to estimate the first Doppler frequency of the first channel, the first channel including a first path, the first Doppler frequency being the Doppler frequency of the first path, and the first Doppler frequency being used to determine the first precoding matrix.

In some implementations, the first reference signal is used to estimate the second Doppler frequency of the first channel, the first channel including a second path, the second Doppler frequency being the Doppler frequency of the second path, and the second Doppler frequency being used to determine the first precoding matrix.

In some implementations, the first information includes a first identifier and a first amplitude, wherein the first amplitude is the amplitude of a first path and the first path is the path corresponding to the first identifier.

In some implementations, the first information includes a second identifier and a second amplitude, wherein the second amplitude is the amplitude of a second path and the second path is the path corresponding to the second identifier.

In some implementations, the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path.

In some implementations, the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path.

In some implementations, the first information indicates the first amplitude, including: the first information indicates the first amplitude and the second amplitude of the first channel.

In some implementations, after transmitting first information on the first channel, the method includes: receiving first data, which has been processed by a second precoding matrix, the second precoding matrix being determined based on the first amplitude and the second amplitude.

In some implementations, after transmitting first information on the first channel, the method includes: receiving first data, which has been processed by a second precoding matrix determined based on the first amplitude.

In some implementations, the first reference signal includes SRS, and the second reference signal includes CSI-RS.

Thirdly, a communication device is provided, including processing circuitry (or a processor) and an input/output interface (also referred to as an interface circuit), the input/output interface being used for inputting and/or outputting signals, the processing circuitry being used to perform the first aspect and any possible method of the first aspect, or the processing circuitry being used to perform the second aspect and any possible method of the second aspect.

In some implementations, the processing circuitry is used to communicate with other devices via an interface circuitry and to perform the first aspect and any possible method of the first aspect, or to perform the second aspect and any possible method of the second aspect.

Fourthly, a communication device is provided. This communication device can implement the first aspect and any possible implementation thereof, or it can implement the second aspect and any possible implementation thereof.

In some implementations, the communication device may include modules, units, or means for performing the methods/operations/steps/actions described in the first aspect and any possible implementation of the first aspect. These modules, units, or means may be hardware circuits, software, or a combination of hardware circuits and software.

In some implementations, the communication device includes a processing unit and a transceiver unit. The transceiver unit is used to receive a first reference signal; the processing unit is used to determine a first precoding matrix based on the first reference signal; the transceiver unit is used to transmit a second reference signal, which is processed by the first precoding matrix, and the second reference signal is used to estimate a first amplitude of a first channel; the transceiver unit is used to receive first information on the first channel, the first information indicating the first amplitude.

In some implementations, the processing unit is configured to estimate a first Doppler frequency of the first channel based on the first reference signal, the first channel including a first path, the first Doppler frequency being the Doppler frequency of the first path; the processing unit is configured to determine the first precoding matrix based on the first Doppler frequency.

In some implementations, the processing unit is configured to estimate a first Doppler frequency and a second Doppler frequency of the first channel based on the first reference signal, the first channel including a first path and a second path, the first Doppler frequency being the Doppler frequency of the first path, and the second Doppler frequency being the Doppler frequency of the second path; the processing unit is configured to determine the first precoding matrix based on the first Doppler frequency and the second Doppler frequency.

In some implementations, the processing unit is used to obtain the first angular delay domain information of the first path based on the first reference signal; the processing unit is used to determine the first precoding matrix based on the first Doppler frequency and the first angular delay domain information.

In some implementations, the processing unit is used to obtain first angular delay domain information of the first path and second angular delay domain information of the second path based on the first reference signal; the processing unit is used to determine the first precoding matrix based on the first Doppler frequency, the first angular delay domain information, the second Doppler frequency and the second angular delay domain information.

In some implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second matrix indicates the first angular delay domain information.

In some implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second Doppler frequency, and the second matrix indicates the first angular delay domain information and the second angular delay domain information.

In some implementations, the first channel comprises S paths, where S is a positive integer greater than or equal to 1, and the first precoding matrix F satisfies:

F = ( D T) -1 (E T ) -1 ;

D＝[d ₁ ,…,d _i ,…,d _s ];

Where i and j are integers, 1≤i≤S, 1≤j≤S; (E ^T ) ^-1 is the first matrix, e _j is the first Doppler frequency; (D ^T ) ^-1 is the second matrix, d _i is the first angular time delay domain information; "T" indicates matrix transpose, and "-1" indicates matrix inversion.

In some implementations, the first information includes a first identifier and a first amplitude, wherein the first amplitude is the amplitude of a first path and the first path is the path corresponding to the first identifier.

In some implementations, the first information includes a second identifier and a second amplitude, wherein the second amplitude is the amplitude of a second path and the second path is the path corresponding to the second identifier.

In some implementations, the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path.

In some implementations, the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path.

In some implementations, the first information indicates the first amplitude, including: the first information indicates the first amplitude and the second amplitude of the first channel.

In some implementations, the transceiver unit is used to receive first data, which is processed by a second precoding matrix, which is determined based on the first amplitude and the second amplitude.

In some implementations, the transceiver unit is used to receive first data, which is processed by a second precoding matrix, which is determined based on the first amplitude.

In some implementations, the first reference signal includes SRS, and the second reference signal includes CSI-RS.

In some implementations, the communication device may include modules, units, or means for performing the methods/operations/steps/actions described in the second aspect and any possible implementation of the second aspect, which may be hardware circuits, software, or a combination of hardware circuits and software.

In some implementations, the communication device includes a processing unit and a transceiver unit. The transceiver unit is used to transmit a first reference signal for determining a first precoding matrix; the transceiver unit is used to receive a second reference signal processed by the first precoding matrix; the processing unit is used to estimate a first amplitude of a first channel based on the second reference signal; and the transceiver unit is used to transmit first information on the first channel, the first information indicating the first amplitude.

In some implementations, the first reference signal is used to estimate the first Doppler frequency of the first channel, the first channel including a first path, the first Doppler frequency being the Doppler frequency of the first path, and the first Doppler frequency being used to determine the first precoding matrix.

In some implementations, the first reference signal is used to estimate the second Doppler frequency of the first channel, the first channel including a second path, the second Doppler frequency being the Doppler frequency of the second path, and the second Doppler frequency being used to determine the first precoding matrix.

In some implementations, the first information includes a first identifier and a first amplitude, wherein the first amplitude is the amplitude of a first path and the first path is the path corresponding to the first identifier.

In some implementations, the first information includes a second identifier and a second amplitude, wherein the second amplitude is the amplitude of a second path and the second path is the path corresponding to the second identifier.

In some implementations, the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path.

In some implementations, the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path.

In some implementations, the first information indicates the first amplitude, including: the first information indicates the first amplitude and the second amplitude of the first channel.

In some implementations, the transceiver unit is used to receive first data, which is processed by a second precoding matrix, which is determined based on the first amplitude and the second amplitude.

In some implementations, the transceiver unit is used to receive first data, which is processed by a second precoding matrix, which is determined based on the first amplitude.

In some implementations, the first reference signal includes SRS, and the second reference signal includes CSI-RS.

Fifthly, a computer-readable storage medium is provided that stores a computer program or instructions that, when executed, cause the first aspect and any possible method of the first aspect to be performed (or implemented), or cause the second aspect and any possible method of the second aspect to be performed (or implemented).

In a sixth aspect, a computer program product is provided, comprising a computer program or instructions that, when executed, cause the first aspect and any possible method of the first aspect to be performed (or implemented), or cause the second aspect and any possible method of the second aspect to be performed (or implemented).

A seventh aspect provides a communication device, including a processor configured to execute any of the possible methods of the first aspect above, or to execute any of the possible methods of the second aspect above, by executing a computer program (or computer-executable instructions) stored in a memory, and/or by logic circuitry.

In one possible implementation, the device also includes a memory. In another possible implementation, the processor and memory are integrated together. In yet another possible implementation, the memory is located outside the communication device. The processor may include one or more processors.

In one possible implementation, the communication device further includes a communication interface for communicating with other devices, such as transmitting or receiving data and/or signals. Exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

In one implementation, the communication device of the third, fourth, or seventh aspect mentioned above can be a chip or a chip system.

Eighthly, a chip is provided, including a processor for calling a computer program or computer instructions in memory to cause the processor to execute any of the implementations of the first aspect above, or to cause the processor to execute any of the implementations of the second aspect above.

In some implementations, the processor is coupled to the memory via an interface.

Ninth aspect, a communication system is provided, including a first device and a second device, the first device being configured to perform the first aspect and any possible implementation thereof, and the second device being configured to perform the second aspect and any possible implementation thereof.

In a tenth aspect, a computer program is provided, comprising computer instructions that, when executed, cause the first aspect and any possible method of the first aspect to be performed (or implemented), or cause the second aspect and any possible method of the second aspect to be performed (or implemented).

The description of the beneficial effects of any of the second to tenth aspects can be referred to the description of the beneficial effects of the first aspect.

Attached Figure Description

Figure 1 is a schematic diagram of a communication system.

Figure 2 is a schematic diagram of another communication system.

Figure 3 is a schematic flowchart of a communication method.

Figure 4 is a schematic flowchart of another communication method.

Figure 5 is a schematic flowchart of a communication method provided in an embodiment of this application.

Figure 6 is a schematic block diagram of a communication device according to an embodiment of this application.

Figure 7 is a schematic block diagram of another communication device according to an embodiment of this application.

Detailed Implementation

The technical solutions in this application will now be described with reference to the accompanying drawings.

This application will present various aspects, embodiments, or features relating to systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and/or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

Furthermore, in the embodiments of this application, words such as "exemplary" and "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" in this application should not be construed as being better or more advantageous than other embodiments or designs. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

The business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

References to "one embodiment" or "some embodiments" as used in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

The descriptions of "first," "second," etc., appearing in the embodiments of this application are for illustrative purposes and to distinguish the objects being described, unless otherwise specified. They are not in any particular order and do not indicate any special limitation on the number of objects in the embodiments of this application, nor do they constitute any limitation on the embodiments of this application.

It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

It is understandable that the term "and/or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character "/" in this article generally indicates that the preceding and following related objects have an "or" relationship.

The technical solutions of this application can be applied to various communication systems, including but not limited to: long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, new radio (NR) systems, and other fifth ^- generation (5G) mobile communication systems, narrowband internet of things (NB-IoT) systems, enhanced machine-type communication (eMTC) systems, enhanced mobile broadband (eMBB) systems, ultra-reliable low latency communications (URLLC) systems, satellite communication systems, LTE-machine-to-machine (LTE-M) systems, or ^sixth -generation (6G) mobile communication systems and other systems evolved after 5G.

In the embodiments of this application, the term "communication" can also be described as "data transmission," "signal transmission," "information transmission," or simply "transmission." In the embodiments of this application, transmission can include sending or receiving. Exemplarily, transmission can be uplink transmission, such as a terminal device sending a signal to a network device; transmission can also be downlink transmission, such as a network device sending a signal to a terminal device; transmission can also be sidelink transmission, such as a terminal device sending a signal to another terminal device. Exemplarily, "transmission" can be air interface-level transmission, or it can refer to signal transmission at a chip input (I)/output (O) interface, rather than air interface-level transmission.

Figure 1 is a schematic diagram of a communication system 100. As shown in Figure 1, the communication system 100 includes a wireless access network 110 and a core network 120. Optionally, the communication system 100 may also include an Internet 130. The wireless access network 110 may include at least one network device (111a and 111b in Figure 1) and at least one terminal device (112a-112j in Figure 1). The terminal device is connected to the network device wirelessly. The network device is connected to the core network 120 wirelessly or via a wired connection. The core network 120 may include one or more core network devices. The core network device and the network device may be independent physical devices, or the functions of the core network device and the logical functions of the network device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the network device. Terminal devices and network devices can be interconnected via wired or wireless means. Terminal devices can communicate wirelessly with each other, network devices with each other, and terminal devices with each other via air interface resources. For example, air interface resources may include at least one of time-domain resources, frequency-domain resources, code resources, and spatial resources. It should be noted that Figure 1 is only a schematic diagram, and the communication system 100 may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1.

Network devices can be any type of device with wireless transceiver capabilities. For example, a network device can be a base station used to connect terminal devices to a radio access network (RAN). Network devices are sometimes also referred to as access network devices or access network nodes. It is understood that the names of devices with network device functionality may differ in systems employing different wireless access technologies. For ease of description, the embodiments of this application collectively refer to devices providing wireless communication access functionality to terminal devices as base stations. In the embodiments of this application, network devices include, but are not limited to: various forms of macro base stations (as shown in Figure 1, 111a), micro base stations or indoor stations (as shown in Figure 1, 111b), pico base stations, small stations, balloon stations, relay stations, access points, etc. Network equipment can include evolved node Bs (eNBs or eNodeBs) in LTE, access points (APs), wireless relay nodes, wireless backhaul nodes, transmission points (TPs), or transmission reception points (TRPs) in WiFi systems. It can also include next-generation node Bs (gNBs) or transmission points (TRPs or TPs) in 5G systems, one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, and network nodes constituting a gNB or transmission point, such as baseband units (BBUs) or distributed units (DUs). Furthermore, it can include network equipment, servers, or vehicle-mounted equipment in networks evolving beyond 5G, such as 6G. Network equipment can also be modules or units that perform some of the functions of a base station; for example, it can be a central unit (CU) or a DU.

For example, in a universal mobile telecommunications system (UMTS) or LTE wireless communication system, the network device can be a macro base station (eNB); in a heterogeneous network (HetNet) scenario, the network device can be a micro base station (eNB); in a distributed base station scenario, the network device can include a base station unit (BBU) and a remote radio unit (RRU); in a cloud radio access network (CRAN) scenario, the network device can be a BBU pool and an RRU; and in future wireless communication systems, the network device can be a gNB.

In this embodiment, the means for implementing the function of the network device can be the network device itself, or it can be a means that enables the network device to implement the function, such as a chip system, which can be installed in the network device. The chip system can be composed of chips, or it can include chips and other discrete components.

In another possible scenario, multiple network devices collaborate to assist the terminal in achieving wireless access, with each network device performing a portion of the base station's functions. For example, network devices could be CUs, DUs, CUs (control plane, CP), CUs (user plane, UP), or radio units (RUs). CUs and DUs can be separate entities or included in the same network element, such as a BBU. RUs can be included in radio equipment or radio units, such as RRUs, active antenna units (AAUs), or remote radio heads (RRHs).

In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (O-RAN) system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules. The embodiments of this application do not limit the specific technology or specific device form used in the network device.

Terminal equipment can be a device that provides voice and/or data connectivity to users; it can also be a device with wireless connectivity. Terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water (such as on ships); and it can also be deployed in the air (such as on airplanes, balloons, and satellites). Terminal equipment can also be referred to as user equipment (UE), access terminal, terminal, subscriber unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, wireless network equipment, user agent, or user device. In this application embodiment, the terminal device includes, but is not limited to: cellular phone, mobile phone, wireless data card, wireless modem, tablet computer, laptop computer, notebook computer, handheld computer, mobile internet device (MID), computer with wireless transceiver function, cordless phone, session initiation protocol (SIP) phone, smart phone, wireless local loop (WLAN). Alloop (WLL) stations, personal digital assistants (PDAs), handsets with wireless communication capabilities, computing devices or other devices connected to wireless modems, in-vehicle devices (e.g., cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), wearable devices (e.g., smartwatches, smart bracelets, pedometers, smart glasses, etc.), satellite terminals, terminal devices in the Internet of Things or the Internet of Vehicles, as well as any form of terminal in future networks, relay user equipment, or terminals in future evolved public land mobile networks (PLMNs), etc. Terminal devices can also be virtual reality (VR) devices, augmented reality (AR) devices, smart point-of-sale (POS) machines, customer-premises equipment (CPE), light user equipment (UE), reduced capability user equipment (REDCAP UE), machine-type communication (MTC) terminals, and industrial control devices. Terminal devices can be categorized into terminal devices in various fields, including autonomous driving, remote medical care, smart grids, transportation safety, smart cities, smart homes, tactile devices, smart home devices (e.g., refrigerators, televisions, air conditioners, electricity meters), intelligent robots, robotic arms, workshop equipment, wireless terminals in autonomous driving, and flying devices (e.g., intelligent robots, hot air balloons, drones, airplanes). Terminal devices can also be vehicle-mounted devices, such as complete vehicle units, vehicle modules, vehicle communication modules, vehicle chips, on-board units (OBUs), or telematics boxes (T-BOXs). They can also be other devices with terminal functions, such as devices acting as terminals in device-to-device (D2D) communication. Terminal devices can also be other embedded communication modules. This application does not limit the scope of the embodiments.

In this application embodiment, the device for implementing the functions of the terminal device can be the terminal device itself, or it can be any device capable of supporting the terminal device in implementing the functions, such as a chip or chip system. This device can be installed in the terminal device. The chip system can consist of chips or include chips and other discrete components. In the technical solution of this application embodiment, the device for implementing the functions of the terminal device is referred to as the terminal device, which can also be called a terminal. The following description may use a UE (User Equipment) as an example to illustrate the technical solution provided in this application embodiment.

The roles of base stations and terminals can be relative. For example, the helicopter or drone 112i in Figure 1 can be configured as a mobile base station. For terminals 112j that access the wireless access network 110 via 112i, terminal 112i is a base station; however, for base station 111a, 112i is a terminal, meaning that 111a and 112i communicate via a wireless air interface protocol. Of course, 111a and 112i can also communicate via a base station-to-base station interface protocol. In this case, relative to 111a, 112i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 111a and 111b in Figure 1 can be called communication devices with base station functions, and 112a-112j in Figure 1 can be called communication devices with terminal functions.

Network devices and terminal devices can communicate via wireless links. The transmission link from a network device to a terminal device can be called a downlink (DL) or downlink channel, used for transmitting downlink signals. The transmission link from a terminal device to a network device can be called an uplink (UL) or uplink channel, used for transmitting uplink signals. The transmission link from a terminal device to another terminal device can be called a sidelink (SL) or sidelink channel.

For example, considering the transmission from the UMTS terrestrial radio access network (UTRAN) to the UE (UTRANtoUE, Uu) interface, the two parties in the wireless communication can include network equipment and terminal equipment; considering the SL air interface transmission, both parties in the wireless communication can be terminal equipment.

Figure 2 is a schematic diagram of another communication system. Figure 2(a) to (c) illustrate three communication scenarios. The dashed circles represent the coverage area of the network device. Devices located within the dashed circles are within the coverage area of the network device; devices located outside the dashed circles are outside the coverage area of the network device.

The technical solutions provided in this application can be applied to D2D communication, vehicle-to-infrastructure/vehicle/pedestrian (V2X) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), Internet of Things (IoT) communication systems, or other communication systems. Among these, cellular vehicle-to-everything (C-V2X) can be a V2X communication technology developed based on cellular systems. C-V2X can utilize and enhance the functions and elements of cellular networks to achieve low-latency and high-reliability communication between various nodes in the vehicle network. C-V2X can include vehicle-to-vehicle (V2V) communication, vehicle-to-pedestrian (V2P) communication, vehicle-to-infrastructure (V2I) communication, and vehicle-to-network (V2N) communication.

When applied to systems where users communicate directly (e.g., V2X, D2D), this application is applicable to both network-covered and non-network-covered communication scenarios. Users can choose the resource mode themselves. The terminal device (or user terminal) can be within or outside the network device's coverage area.

Referring to Figure 2(a), the two communicating terminal devices (shown in the form of a vehicle in Figure 2) can be within the coverage area of the network device. For example, one terminal device can communicate with another terminal device via a proximity-based services communication 5 (PC5) interface.

Referring to Figure 2(b), one of the two terminal devices communicating (shown in the form of a vehicle in Figure 2) can be within the coverage area of the network device, while the other can be outside the coverage area of the network device.

Referring to Figure 2(c), the two terminal devices communicating (shown in the form of a vehicle in Figure 2) can both be outside the coverage area of the network device.

Figure 3 is a schematic flowchart of a communication method 300. Figure 3 is for illustrative purposes only and does not constitute a limitation of this application. The method 300 shown in Figure 3 can be used for precoding based on the weights of the precoding matrix indication (PMI) (hereinafter referred to as "PMI weights"). For ease of description, it is assumed below that the number of CSI-RS ports is 32, the number of antennas of the network device is 64, the number of antennas of the terminal device is 4, and the rank of the channel is 2. Furthermore, the following description uses a gNB as the network device and a UE as the terminal device as an example.

Method 300 can be broadly divided into two parts: PMI acquisition and PMI usage. The UE can select one or more of the best orthogonal beams from a finite number of beams in the codebook based on the CSI-RS. The UE can feed back the PMI to the gNB, which indicates the one or more orthogonal beams selected by the UE (or PMI weights). These one or more orthogonal beams may include a precoding matrix. The gNB can select the optimal PMI weights based on the PMIs fed back by the UE uplink. The gNB can precode the data-carrying signal according to the optimal PMI weights and send the processed signal to the UE, thereby enabling the gNB to transmit data to the UE.

In this context, a beam can refer to the electromagnetic radiation pattern of an antenna system. Beamforming is the process of forming a beam. In a multi-antenna system, beamforming can be a process of adjusting the amplitude or phase of signals on the radio frequency link to form a directional electromagnetic radiation direction.

S310, the gNB sends a CSI-RS to the UE. Correspondingly, the UE receives the CSI-RS from the gNB.

For example, the gNB has 64 antennas. Therefore, when CSI-RS uses 32 ports, the gNB can map the CSI-RS signal on the 32 ports onto the 64 antennas according to a 64x32 weight matrix W. This weight matrix W can also be called the CSI-RS weight matrix.

S320, the UE determines the CSI based on the CSI-RS.

Optionally, CSI may include a rank indicator (RI), a channel quality indicator (CQI), and a precoding matrix (PMI). RI can represent the number of multiple-input multiple-output (MIMO) layers. CQI can indicate the channel quality. PMI can indicate the precoding matrix.

For example, the UE can identify up to 32 CSI-RS ports, therefore, the channel matrix that the UE can measure is 4 rows and 32 columns. The UE can determine the appropriate downlink transmission layer number on the current channel based on the measured channel matrix. This downlink transmission layer number can be represented by RI. The UE can determine the precoding matrix based on this RI. Then, the UE can feed back the appropriate precoding matrix to the gNB. To reduce implementation complexity, the precoding matrix can be quantized into a finite number of values, which can be called a codebook. Each value in the codebook can be assigned a number, so the UE only needs to feed back these codebook numbers, and the gNB can determine the precoding matrix corresponding to that number. These numbers can also be called PMIs.

S330, the UE sends a CSI report to the gNB. Correspondingly, the gNB receives the CSI report from the UE.

Optionally, CSI reports may indicate CSI. For example, CSI reports may include RI, CQI, and PMI.

S340, gNB is pre-encoded according to CSI.

Before transmitting data, the gNB can weight the data on the PDSCH port based on the codebook corresponding to the PMI in the CSI report. Assuming the rank of the channel matrix is 2, the weighting matrix _WPMI can be a 32-row, 2-column matrix. This weighting matrix _WPMI can also be called the PMI weight matrix (or PMI weight, or precoding matrix).

S350, the gNB sends data to the UE. Correspondingly, the UE receives data from the gNB.

For example, the gNB can transmit data to the UE via the physical downlink shared channel (PDSCH). Assuming the gNB has 64 antennas, the data on the PDSCH port, after being weighted by the PMI weight matrix, can also be mapped using a similar method to mapping the CSI-RS signal to the 64 antennas. This involves a second weighting using the CSI-RS weight matrix, thereby adjusting the weights of the data on the PDSCH port across the 64 antennas. This process enables data transmission on a beam in a specified direction.

Figure 4 is a schematic flowchart of another communication method 400. Figure 4 is for illustrative purposes only and does not constitute a limitation of this application. The method 400 shown in Figure 4 can be used for precoding based on the weights of the SRS (hereinafter referred to as "SRS weights"). The following description uses a gNB as the network device and a UE as the terminal device as an example.

S410, the UE sends an SRS to the gNB. The gNB receives the SRS from the UE.

S420 and gNB perform channel estimation based on SRS.

For example, the gNB can measure and receive the uplink SRS transmitted by the UE through its antenna. The gNB can estimate the uplink channel matrix _Hul based on the SRS. Optionally, the channel matrix _Hul can include uplink channel information in all dimensions.

S430, gNB performs precoding based on the channel estimation results.

Optionally, the gNB can determine the downlink channel matrix H _{_dl} as the uplink channel matrix H_{_ul} based on the reciprocity of the uplink and downlink channels. The gNB can determine the number of data streams (or MIMO layers) based on the rank of the channel matrix. The gNB can then determine the weighting matrix W_{_SRS} based on the number of MIMO layers and the downlink channel matrix H_{_dl} . This weighting matrix W_{_SRS} can also be called the SRS weight matrix (or SRS weights, or precoding matrix).

S440, the gNB sends data to the UE. Correspondingly, the UE receives data from the gNB.

Assuming the gNB has 64 antennas, the data from the PDSCH port, after being weighted by the SRS weight matrix, can be mapped to the 64 antennas using a similar method to mapping the CSI-RS signal. This involves a second weighting using the CSI-RS weight matrix, thus adjusting the weights of the data from the PDSCH port to the 64 antennas. This process enables data transmission on a beam in a specified direction.

In other possible formulations, the precoding matrix can be the matrix obtained by multiplying the PMI weights by the CSI-RS weight matrix. Alternatively, the precoding matrix can be the matrix obtained by multiplying the SRS weights by the matrix mapped to the corresponding PDSCH ports. The dimension of the precoding matrix is related to the number of gNB transmit antennas and ports. By adjusting the precoding matrix, the gNB can adjust the weights of the data on the antenna ports, thereby achieving beamforming in a specified direction.

When the channel quality is poor, terminal devices or network devices may have difficulty accurately estimating the channel, thus making it impossible to apply appropriate precoding to process the data to be transmitted, and making it difficult to guarantee the data transmission performance.

For example, poor channel quality at the cell edge leads to severe SRS or CSI-RS interference. Using methods 300 or 400, accurate channel estimation is difficult. Inaccurate channel estimation prevents the application of appropriate precoding to the data to be transmitted. For instance, in scenarios where terminal devices move rapidly, inappropriate precoding can cause the transmitted beam to misalign with the terminal device, thus reducing data transmission performance. Consequently, when terminal devices move at high speeds at the cell edge, data transmission performance between the terminal device and network devices is poor.

Therefore, how to accurately estimate the channel is an urgent problem to be solved.

Figure 5 is a schematic flowchart of a communication method 500 provided in an embodiment of this application. Method 500 can accurately perform channel estimation, thereby improving data transmission performance. Optional operations in method 500 are indicated by dashed lines in Figure 5. Method 500 is described below with reference to Figure 5.

S510, the first device receives a first reference signal from the second device. Correspondingly, the second device sends the first reference signal to the first device.

Unless otherwise specified, the term "first device" in this application may refer to the first device itself (e.g., a network device or a terminal device), a component within the first device (e.g., a processor, a chip, or a chip system), or a logic module or software capable of implementing all or part of the functions of the first device. For ease of description, the first device will be used as an example in the following description.

Unless otherwise specified, the term "second device" in this application can refer to the second device itself (e.g., a terminal device), a component within the second device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the second device. Exemplarily, the second device can be a vehicle, a wireless communication module within a vehicle, an in-vehicle telematics box (T-box), a computer with wireless transceiver capabilities, a tablet computer, a wireless terminal in autonomous driving, or hardware, software, or a combination of hardware and software in a wireless terminal device in a smart city. For ease of description, the following description uses the second device as an example.

As an example, the first device can be a network device, and the second device can be a terminal device. As another example, both the first and second devices can be terminal devices. For instance, in scenarios such as V2X or D2D, both the first and second devices can be terminal devices.

For example, the first reference signal may include an SRS. However, this application is not limited to this, and the first reference signal may also be other signals. Furthermore, this application does not limit the specific name of the first reference signal; the first reference signal may be called a reference signal, signal, uplink reference signal, probe signal, or have other names.

In some possible implementations, the second device may periodically send a first reference signal to the first device. In other possible implementations, the first device may send instruction information to the second device, the instruction information being used to instruct the second device to send the first reference signal to the first device; the second device may send the first reference signal to the first device according to the instruction information.

S520, the first device determines the first precoding matrix based on the first reference signal.

In some possible implementations, the first device can perform channel estimation based on a first reference signal and determine a first precoding matrix based on the channel estimation result. This first precoding matrix is related to the channel conditions between the first and second devices, thereby enabling the signal processed by the first precoding matrix to be transmitted in a manner more adapted to the channel. In other possible implementations, the first device can determine the location information of the second device based on the first reference signal and determine the first precoding matrix based on the location information of the second device. This first precoding matrix is related to the location of the second device, thereby enabling the signal processed by the first precoding matrix to be more "aligned" with the second device.

It is understood that the first reference signal can be used to determine the first precoding matrix; however, this application does not limit the elements used to determine the first precoding matrix to include only the first reference signal. The first apparatus can determine the first precoding matrix based on the first reference signal and other elements. For example, the first apparatus can determine the first precoding matrix based on the first reference signal and the CSI-RS weight matrix. In this way, the first precoding matrix can not only reflect the channel characteristics of the first reference signal, but also realize the mapping of antenna ports.

S530, the first device sends a second reference signal to the second device. Correspondingly, the second device receives the second reference signal from the first device.

For example, the second reference signal may be CSI-RS. However, this application is not limited to this, and the second reference signal may also be other signals. In addition, this application does not limit the specific name of the second reference signal, and the second reference signal may be called a reference signal, signal, downlink reference signal, or have other names.

Optionally, the second reference signal is processed by the first precoding matrix. For example, the second reference signal is transmitted according to the first precoding matrix. In some possible implementations, the first device transmits the second reference signal to the second device according to the first precoding matrix. For example, the first device can precode (or weight, or beamforming) the second reference signal according to the first precoding matrix so that the beam of the second reference signal is aligned with the first device.

The first precoding matrix is determined by the first reference signal. Optionally, the channel of the first reference signal and the channel of the second reference signal are the same or approximately the same. In some possible implementations, the first device receives the first reference signal on the first channel. The first device transmits the second reference signal on the same first channel. The term "channel" can be understood as a port, or an antenna port, etc. It is understood that the parameters of a channel can fluctuate within an acceptable error range. For example, the transmission of the first reference signal and the transmission of the second reference signal are not performed simultaneously. The parameters of the channel may change over time. Within an acceptable error range, those skilled in the art can consider the channel through which the first reference signal is transmitted and the channel through which the second reference signal is transmitted to be the same channel.

This application does not limit the specific name of the first precoding matrix, which may also be called a precoding matrix, precoder, downlink proprietary pilot precoding, or other names.

Optionally, the first reference signal and the second reference signal are used to estimate different parameters. For example, the first reference signal can be used to estimate the Doppler frequency (or Doppler frequency shift); the second reference signal can be used to estimate the amplitude.

Optionally, the second reference signal includes first indication information indicating that the second reference signal has undergone precoding processing. For example, the first indication information indicates that the second reference signal has undergone a first precoding process. In this way, the second device can determine that the second reference signal has undergone precoding processing based on the first indication information in the received second reference signal, thereby triggering the second device to estimate and report the corresponding parameters (e.g., amplitude).

This application does not limit the specific name of the first instruction information, which may also be referred to as instruction information, information, identifier, flag, or other names.

Optionally, the first device sends a reference signal (e.g., CSI-RS) to the second device. This reference signal includes a first field indicating whether the reference signal has undergone precoding. Thus, based on the first field in the received reference signal, the second device can determine whether the reference signal has undergone precoding, thereby triggering the second device to perform or not perform estimation and reporting of the corresponding parameter (e.g., amplitude). For example, the second reference signal includes a first field, and the first indication information can be carried in the first field. This application does not limit the specific name of the first field; the first field can also be called a field or a flag.

As one example, the first field can be 1 bit. This bit indicates 0, meaning the reference signal has not been pre-coded. This bit indicates 1, meaning the reference signal has been pre-coded. As another example, the first field can be 1 bit. This bit indicates 1, meaning the reference signal has not been pre-coded. This bit indicates 0, meaning the reference signal has been pre-coded.

Optionally, the first device transmits a second reference signal on a first resource. The first resource can be the resource corresponding to the pre-encoded reference signal. Thus, when the second device receives the second reference signal on the first resource, it can determine that the second reference signal has been pre-encoded, thereby triggering the second device to estimate and report the corresponding parameters (e.g., amplitude). In other words, the first device can transmit the pre-encoded reference signal on a specific resource. If the reference signal received by the second device is received on a specific resource, it triggers the second device to estimate and report the corresponding parameters based on the reference signal; if the reference signal received by the second device is received on other resources (i.e., resources other than the aforementioned specific resource), the second device processes the reference signal in a conventional manner. In some possible implementations, the first device sends at least one of radio resource control (RRC) signaling, media access control (MAC) control element (CE), or downlink control information (DCI) to the second device, wherein at least one of the RRC signaling, MAC CE, or DCI indicates that the first resource corresponds to a precoded reference signal.

S540, the second device estimates the first amplitude of the first channel based on the second reference signal.

For example, the second device may use the least squares method to estimate the second reference signal to obtain a first amplitude of the first channel. The first channel may be the channel of the second reference signal.

S550, the second device sends first information to the first device on the first channel. Correspondingly, the first device receives the first information from the second device on the first channel.

For example, the first channel may correspond to the first antenna port or the first port, and the second device may send the first information to the first device on the first antenna port or the first port.

Optionally, the first information indicates the first amplitude. Optionally, the first information indicates at least one amplitude of the first channel. Wherein, at least one amplitude of the first channel may include the first amplitude.

Optionally, the first information is carried in uplink control information (UCI) or MACCE. However, this application is not limited to this, and the first information may also be carried in other information. Optionally, the first information is carried in the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH).

In some possible implementations, the first information can be direct indication information, meaning the first information includes the first amplitude. In other possible implementations, the first information can be indirect indication information, allowing the receiver to determine the first amplitude based on this first information. For example, the receiver can pre-obtain the mapping relationship between the first amplitude and an identifier. The first information can include the identifier, allowing the receiver to determine that the amplitude corresponding to the identifier is the first amplitude.

The above scheme allows the reference signal used to estimate the channel amplitude to be processed by a precoding matrix. This results in higher transmission quality for the reference signal; for example, the beam of the reference signal can be aligned with the receiver. This scheme enables the receiver to perform more accurate channel estimation based on the high-quality transmitted reference signal. Those skilled in the art will understand that accurate channel parameters can improve data transmission performance. Therefore, the above scheme supports improved data transmission performance.

In some possible implementations, S520 includes: the first device estimating a first Doppler frequency of the first channel based on the first reference signal; and the first device determining the first precoding matrix based on the first Doppler frequency.

For example, the first device may process the first reference signal using the matrix pencil method to estimate the first Doppler frequency of the first channel. For instance, the channel matrix of the first channel may be subjected to singular generalized eigenvalue decomposition, and the resulting singular values may include the first Doppler frequency. The first precoding matrix may be correlated with the first Doppler frequency.

Optionally, the first channel includes a first path, and the first Doppler frequency is the Doppler frequency of the first path.

The first channel may include at least one path, and the first path may be any one of the at least one paths. The first path may be one or more paths. This application does not limit the specific name of the first Doppler frequency, which may also be referred to as Doppler frequency shift, frequency, frequency shift, or other names.

For ease of description, the following example uses a multipath channel model in the angle delay domain. In the angle delay domain, estimating the first channel requires obtaining the Doppler frequency and amplitude of each path of the first channel. However, those skilled in the art will understand that this application can also be applied to other channel models. The uplink channel matrix of the channel model in the angle delay domain is shown in Equation 1.

Where _hUL represents the uplink channel matrix of the first channel. _Nt represents the number of antennas in the first device, and _Nf represents the number of subcarriers. This represents the amplitude of at least one uplink path in the first channel. Let represent the Doppler frequency of at least one path in the uplink of the first channel, and q _{_i} represent the uplink angular delay vector. i can be an integer from 1 to N _{_t} N_{_f}. "N_tN_{_f}" can represent the product of N _{_t} and N_{_f}. M can represent the subcarrier gain. The approximate superposition order, where, m is an integer from 1 to M.

M can be predefined, configured, or pre-configured. "Predefined" can be understood as standard-defined, requiring no configuration from other devices (and cannot be changed by network devices or other terminal devices). In this case, M is information pre-recorded/written in the terminal device's hardware and/or software. "Configuration" is divided into network device configuration and terminal device configuration. For network device configuration, it can be changed via system information block (SIB) or RRC signaling; for terminal device configuration, it can be changed via PC5-RRC signaling. "Pre-configured" can be understood as information pre-recorded/written in the terminal device's hardware and/or software, determined by the manufacturer, and can be changed via software or hardware. M can also be dynamically indicated by the first device.

Each set of values for m and i can represent a path. Therefore, in the channel model shown in Formula 1, the first channel can have N _{_t} N_{_f}M paths. The first path can be any one or more of these N _{_t} N_{_f}M paths. For example, if the first path corresponds to m=1 and i=1, then the first amplitude can be... The first Doppler frequency can be

When the first channel includes multiple paths, the amplitudes of the multiple paths of the first channel can also be referred to as multipath amplitudes.

The first device estimates the first Doppler frequency of the first channel based on the first reference signal, which may include the first device estimating based on the first reference signal. Where 1≤i≤N _t N _f , 1≤m≤M, and i and m are integers.

Since the dimension of the channel matrix is related to the number of antennas and subcarriers, the number of channel parameters (e.g., Doppler frequencies) that need to be estimated becomes enormous when the number of antennas and subcarriers is large. This increases the time delay for the first device to estimate the Doppler frequencies. In the angular delay domain, signal energy is more concentrated. Most of the channel energy is concentrated on a few antennas and subcarriers. Therefore, during channel estimation, only a few energy-concentrated paths can be estimated, thus approximating an estimate of the entire channel. The approximate uplink channel matrix is shown in Equation 2.

in, This represents the approximate uplink channel matrix of the first channel. N _{_s} represents the number of paths selected. It can be understood that the N_{_s} paths are energy-concentrated paths.

For example, the first device can sort the signals of the first reference signal in each path according to the signal strength of each path, and the total energy of the first N _s paths with the highest intensity can be greater than or equal to a preset proportion of the total energy of the first channel.

The first device estimates the first Doppler frequency of the first channel based on the first reference signal, which may include the first device estimating based on the first reference signal. Where 1≤i≤N _s , 1≤m≤M, and i and m are integers.

Through the above scheme, the first and second devices can jointly perform channel estimation. The first device estimates some parameters, such as the Doppler frequency, using a first reference signal. The second device estimates other parameters, such as the amplitude, using a second reference signal. Compared to a single-end channel estimation scheme, the above scheme enables dual-end channel estimation, thereby achieving more accurate channel estimation.

In some possible implementations, before the first device determines the first precoding matrix based on the first Doppler frequency, the method 500 includes: (S515) the first device acquiring first angular delay domain information of the first path based on the first reference signal.

The first device determines the first precoding matrix based on the first Doppler frequency, including: the first device determines the first precoding matrix based on the first Doppler frequency and the first angular delay domain information.

The first device can determine the angular delay domain information of the first channel based on the first reference signal. For example, the first reference signal has different transmission angles and delays on each path. The angular delay domain information of at least one path of the first reference signal can respectively include the transmission angle and delay of the at least one path. The angular delay domain information of the at least one path can include the uplink angular delay domain information of the first path, that is, the uplink transmission angle and delay of the first path.

The first angular delay domain information can be the uplink angular delay domain information. Thus, the angular delay domain information of at least one path of the aforementioned first reference signal can include the first angular delay domain information of the first path. The first device can determine the downlink angular delay domain information based on the first angular delay domain information, and then determine the first precoding matrix based on the first Doppler frequency and the downlink angular delay domain information.

The first angular delay domain information can be the downlink angular delay domain information. Thus, the first device can determine the downlink angular delay domain information of the first path, i.e., the first angular delay domain information, based on the uplink angular delay domain information of the first path. The first device can determine the first precoding matrix based on the first Doppler frequency and the first angular delay domain information.

The first device can determine the first precoding matrix based on the first Doppler frequency and the first angular delay domain information. However, this application does not limit the elements used to determine the first precoding matrix to only include the first Doppler frequency and the first angular delay domain information. The elements used to determine the first precoding matrix may also include other elements. For example, the first device can determine the first precoding matrix based on the Doppler frequencies and angular delay domain information of multiple paths.

Through the above scheme, the first device can determine the precoding matrix based on the Doppler frequency and angle delay domain information, thus improving the precoding processing effect. In this way, the energy of the reference signal on the path of the amplitude to be estimated is further concentrated, allowing the receiver to perform more accurate channel estimation based on the reference signal.

In some possible implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second matrix indicates the first angular delay domain information.

The first matrix indicates the first Doppler frequency. This can be understood as the first matrix being associated with the first Doppler frequency, or as the first matrix including the first Doppler frequency. For example, one or more elements in the first matrix are the first Doppler frequency, or are related to the first Doppler frequency.

The second matrix indicates the first angle time delay domain information. This can be understood as the second matrix being associated with the first angle time delay domain information, or as the second matrix including the first angle time delay domain information. For example, one or more elements in the second matrix are first angle time delay domain information, or are related to the first angle time delay domain information.

For example, the first precoding matrix can be the product of a Doppler frequency-related matrix and an angle delay domain information-related matrix. For instance, the first precoding matrix is obtained by left-multiplying the first matrix by the second matrix. Alternatively, the first precoding matrix is obtained by left-multiplying the second matrix by the first matrix. The first precoding matrix can be obtained by multiplying only the two matrices mentioned above, or by multiplying more matrices including the two matrices mentioned above, or by performing other operations.

Through the above embodiments, the first precoding matrix can be determined based on the first matrix and the second matrix. The above scheme can improve the efficiency of precoding by associating precoding with Doppler frequency and angular time delay domain information through a simple implementation.

In some possible implementations, the first channel comprises S paths, where S is a positive integer greater than or equal to 1, and the first precoding matrix F satisfies Equations 3 to 5.

F = ( ^D _T ⁾ ^{^-1}(E_T)^{^-1} (Formula 3)

D＝[d ₁ ,…,d _i ,…,d _S ] (Formula 4)

Where i and j are integers, 1≤i≤S, 1≤j≤S; (E ^T ) ^-1 is the first matrix, e _j is the first Doppler frequency; (D ^T ) ^-1 is the second matrix, d _i is the first angular time delay domain information; "T" indicates matrix transpose, and "-1" indicates matrix inversion.

Equations 3 to 5 are derived below. Based on the reciprocity of the uplink and downlink channels, the downlink channel matrix of the multipath channel model in the angle delay domain is shown in Equation 6.

Where _hDL represents the downlink channel matrix of the first channel. This represents the amplitude of at least one downlink path in the first channel. Let represent the Doppler frequency of at least one downlink path in the first channel, and d _{_i} represent the downlink angular delay vector. Other parameters can be found in Equation 1.

Before or during the execution of S520 by the first device, the first device can obtain the uplink Doppler frequency of each path (e.g., the first Doppler frequency of the first path). Due to the reciprocity of the uplink and downlink channels, the downlink Doppler frequency of at least one path of the first channel can be equal to the uplink Doppler frequency of the aforementioned at least one path. Thus, the first device also needs to obtain the downlink amplitude of each path to complete the estimation of the first channel. To better estimate the amplitude, when the first device transmits the second reference signal, it can perform corresponding precoding processing to eliminate the influence of other parameter variables.

Formula 6 can be simplified to Formula 7.

Wherein, matrix D represents the angular delay domain information of at least one path of the first channel. Matrix E represents the downlink Doppler frequency of at least one path of the first channel. Matrix ^ADL represents the downlink amplitude of at least one path of the first channel. S = N _t N _f M.

Thus, the second reference signal _yDL received by the second device can be represented by Equation 8.

y _DL = (h _DL ) ^T FS+n = (A ^DL ) ^T E ^T D ^T FS+n (Formula 8)

Where n represents noise. When applying Equations 3 to 5 to matrix F, the second reference signal _yDL received by the second device can be represented by Equation 9.

y _DL = (A ^DL ) ^T S+n (Formula 9)

Therefore, by precoding the second reference signal according to Formulas 3 to 5, the influence of other parameter variables can be eliminated, enabling the second device to better estimate the amplitude of the first channel (i.e., ^ADL in Formula 8).

The first angle delay domain information of the first path can be uplink angle delay domain information. For example, the first angle delay domain information of the first path can be q_{_i} in Formula 1 or Formula 2. The first angle delay domain information of the first path can also be downlink angle delay domain information. For example, the first angle delay domain information of the first path can be d_{_i} in Formula 6 or Formula 7.

There is a certain correspondence between the uplink angular delay domain information and the downlink angular delay domain information of a path. The first device can determine the downlink angular delay domain information based on the uplink angular delay domain information. For example, the downlink angular delay domain information may include the transmission angle and transmission delay. The first device can determine the transmission angle at which it transmits a signal to the second device based on the reception angle of the first reference signal. The first device can determine that the transmission delay of the signal transmitted from the first device to the second device is the reception delay of the first reference signal. For example, the first device can determine d_{_i} in formula 6 or formula 7 based on q _{_i} in formula 1 or formula 2, thereby obtaining matrix D in formula 4.

Similar to the uplink channel, the downlink channel exhibits a more concentrated signal energy in the angular delay domain. Most of the channel energy is concentrated on a few antennas and subcarriers. Therefore, channel estimation can approximate the entire channel by estimating only the few energy-concentrated paths. The approximate downlink channel matrix is shown in Equation 10.

in, This represents the approximate downlink channel matrix of the first channel. N _′s represents the number of paths selected. It can be understood that the N _′s paths are energy-concentrated paths.

Similar to how Formula 6 is simplified to Formula 7, Formula 10 can be simplified to Formula 11.

Wherein, matrix D represents the angular time delay domain information of at least one path of the first channel. Matrix E represents the downlink Doppler frequency of at least one path of the first channel. Matrix ^ADL represents the downlink amplitude of at least one path of the first channel. S＝N′ _s M.

Thus, the second reference signal _yDL received by the second device can be represented by Equation 12.

When formulas 3 to 5 are applied to matrix F, the second reference signal _yDL received by the second device can be represented by formula 9 above.

In some possible implementations, N _′s in Equation 10 is the same as _Ns in Equation 2. For example, the first device can perform channel estimation on some uplink paths to obtain the Doppler frequencies of these paths; the first precoding matrix determined by the first device is still for these paths, that is, the first device determines the first precoding matrix based on the Doppler frequencies and angular delay domain information of these paths. In this way, the signal strength of the second reference signal received by the second device is enhanced in the aforementioned paths.

In some other possible implementations, N _′s in Equation 10 differs from _Ns in Equation 2. For example, the first precoding matrix determined by the first device can be for other paths, i.e., not limited to _Ns paths. Since the estimation of the first uplink channel and the estimation of the first downlink channel are not performed simultaneously, the energy-concentrated path may have changed when the first downlink channel is estimated. Therefore, the above scheme can update the energy-concentrated path in the channel in a timely manner, allowing the second device to more accurately estimate the amplitude of at least one path of the first channel.

Based on the above scheme, the first precoding matrix can eliminate the influence of other parameter variables of the second reference signal in the first channel, enabling the second device to better estimate the amplitude of the first channel.

In some possible implementations, S520 includes: a first device estimating a first Doppler frequency and a second Doppler frequency of the first channel based on the first reference signal; and the first device determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency.

Optionally, the first channel includes a first path and a second path, the first Doppler frequency is the Doppler frequency of the first path, and the second Doppler frequency is the Doppler frequency of the second path.

The first channel may include multiple paths. These multiple paths may include a first path and a second path. The first path and the second path may be the same or different. For example, the first device may process the first reference signal using a matrix-beam method to estimate the first Doppler frequency and the second Doppler frequency of the first channel. For instance, the channel matrix of the first channel may be subjected to singular generalized eigenvalue decomposition, and the resulting singular values include the first Doppler frequency and the second Doppler frequency. The first precoding matrix may be associated with the first Doppler frequency and the second Doppler frequency.

This application does not limit the specific name of the second Doppler frequency, which may also be referred to as Doppler frequency shift, frequency, frequency shift or other names.

In some possible implementations, before the first device determines the first precoding matrix based on the first Doppler frequency and the second Doppler frequency, the method includes: the first device acquiring first angular delay domain information of the first path and second angular delay domain information of the second path based on the first reference signal.

The first device determines the first precoding matrix based on the first Doppler frequency and the second Doppler frequency, including: determining the first precoding matrix based on the first Doppler frequency, the first angular delay domain information, the second Doppler frequency, and the second angular delay domain information.

The first device can determine the angular delay domain information of the first channel based on the first reference signal. For example, the first reference signal has different transmission angles and delays on each path. The angular delay domain information of the multiple paths of the first reference signal can respectively include the transmission angles and delays of the multiple paths. Specifically, the angular delay domain information of the multiple paths can include the uplink angular delay domain information and the downlink angular delay domain information of the first path, that is, the uplink transmission angle and delay of the first path, and the uplink transmission angle and delay of the second path.

The second angular delay domain information can be the uplink angular delay domain information. Thus, the angular delay domain information of the multiple paths of the aforementioned first reference signal can include the second angular delay domain information of the second path. The first device can determine the downlink angular delay domain information based on the second angular delay domain information, and then determine the first precoding matrix based on the first Doppler frequency, the second Doppler frequency, the downlink angular delay domain information of the first path, and the downlink angular delay domain information of the second path.

The second angular delay domain information can be the downlink angular delay domain information. Thus, the first device can determine the downlink angular delay domain information of the second path, i.e., the second angular delay domain information, based on the uplink angular delay domain information of the second path. The first device can determine the first precoding matrix based on the first Doppler frequency, the second Doppler frequency, the downlink angular delay domain information of the first path, and the second angular delay domain information.

In some possible implementations, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second Doppler frequency, and the second matrix indicates the first angular delay domain information and the second angular delay domain information.

For example, the first encoding matrix can satisfy formulas 3 to 5, where S can be a positive integer greater than or equal to 2. The first Doppler frequency and the second Doppler frequency can be taken from at least two of e_₁ to e_{_S} . The first angular delay domain information and the second angular delay domain information can be taken from at least two of d_₁ to d_{_S} .

In some possible implementations, the first information includes a first identifier and a first amplitude, wherein the first amplitude is the amplitude of a first path and the first path is the path corresponding to the first identifier.

The first path corresponds to the first identifier. In other words, the first path is associated with the first identifier. For example, the first identifier can indicate the first path. Or, for another example, the first identifier can be the identifier of the first path.

Thus, the first information can indicate that the amplitude of the path corresponding to the first identifier is a first amplitude value. The first amplitude value can refer to the first amplitude value itself. For example, the first amplitude value can occupy a fixed number of bits, and the binary number of these bits is used to indicate the first amplitude value itself. However, this application is not limited to this, and the first amplitude value can also be replaced with other information indicating the first amplitude value. For example, the index of the first amplitude value.

For example, the first identifier can be represented as an index. For instance, if the total number of multipaths and their superposition orders is N _tN_{_f} M, the index can be numbered according to this total number, and the first identifier can indicate a value in the index. For example, if N _tN_{_f}M = 2 * 3 * 4, then the index can be an integer between 0 and 24, and the first identifier can be taken from an integer between 0 and 24. Alternatively, the index can reflect the values of N _{_t}, N_{_f}, and M. For example, the first identifier could be (1, 2, 3), representing a path where N _{_t} = 1, N_{_f} = 2, and M = 3.

This application does not limit the specific name of the first identifier, which may also be called an indicator, index, or have other names.

The above scheme allows the first information to include a path identifier, enabling the receiver to determine which path corresponds to the first amplitude. While reducing transmission overhead, this scheme accurately indicates the path corresponding to the amplitude.

In some possible implementations, the first information includes a second identifier and a second amplitude, the second amplitude being the amplitude of a second path, and the second path being the path corresponding to the second identifier.

For example, the first information includes a first identifier, a first amplitude, a second identifier, and a second amplitude. That is, the first information can indicate the amplitude of multiple paths. The description of the second identifier can be found in the preceding description of the first identifier, and will not be repeated here.

In some possible implementations, the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path.

The first index indicates the first amplitude. In other words, the first index corresponds to the first amplitude, or the first index is associated with the first amplitude. For example, the first index can be the index of the first amplitude. For example, the amplitude codebook can be [0.1,0.2,0.3,…,3.1,3.2,…,10], and when the first index indicates 10, the first index can indicate the 10th value in the above amplitude codebook. The amplitude codebook can be predefined, configured, or pre-configured. The amplitude codebook can also be dynamically indicated by the first device.

The above scheme allows the first information to include the path identifier and the amplitude index, enabling the receiver to determine the amplitude using the amplitude index and to identify which path the amplitude belongs to using the path identifier. While further reducing transmission overhead, this scheme accurately indicates the amplitude and the corresponding path.

In some possible implementations, the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path.

For example, the first information includes a first identifier, a first index, a second identifier, and a second index. That is, the first information can indicate multiple paths and indices of the amplitudes of the multiple paths. The description of the second index can be found in the preceding description of the first index, and will not be repeated here.

In some possible implementations, the first information indicates the first amplitude, including: the first information indicates the first amplitude and the second amplitude of the first channel.

The first information indicates the first amplitude, which can be understood as the first information indicating, but not limited to, the first amplitude. The above scheme can be understood as the first information indicating multiple amplitudes. For example, the first information can indicate the amplitudes of multiple paths.

In some possible implementations, after S550, method 500 includes: (S560) the first device sending first data to the second device. Correspondingly, the second device receives the first data from the first device.

Optionally, the first data is processed by a second precoding matrix. For example, the second precoding matrix is determined based on the first amplitude. Alternatively, the second precoding matrix is determined based on both the first and second amplitudes.

The first amplitude (or the first amplitude and the second amplitude) can be used to determine the second precoding matrix; however, this application does not limit the elements used to determine the second precoding matrix to include only the first amplitude (or the first amplitude and the second amplitude). For example, the first device can determine the second precoding matrix based on the amplitudes of multiple paths of the first channel and the Doppler frequency. As another example, the first device can determine the second precoding matrix based on the first amplitude (or the first amplitude and the second amplitude), the first matrix, and the second matrix.

In some possible implementations, prior to S560, method 500 includes: (S555) the first means determining the second precoding matrix.

For example, S550 includes: the first device determining a second precoding matrix based on a first amplitude. As another example, S550 includes: the first device determining a second precoding matrix based on a first amplitude and a second amplitude. Yet another example, S550 includes: the first device determining a second precoding matrix based on a first amplitude, a first matrix, and a second matrix. Still another example, S550 includes: the first device determining a second precoding matrix based on a first amplitude, a second amplitude, a first matrix, and a second matrix.

For example, the first data may be carried in the PDSCH. This application does not limit the specific name of the first data, which may also be referred to as data, downlink data, service data, or have other names.

The second precoding matrix can perform mobility compensation for the second device.

One possible implementation involves the terminal device sending a channel-estimated pilot signal (or reference signal) to the network device. For example, a first reference signal. The network device estimates the angle-delay pair (or angle-delay domain information) and Doppler frequency based on the received pilot or reference signal, constructs the downlink channel based on the distinctness of the angle domain space, designs mobility-specific pilot precoding, and sends the downlink pilot signal (or reference signal) to the terminal device. For example, a second reference signal. The terminal device estimates the multipath amplitude on the angle-delay pair and reports the multipath identifier and corresponding amplitude parameters. The network device designs a precoding matrix for transmission based on the estimated Doppler frequency and the amplitude parameters fed back by the terminal device. The network device in the above implementation can be replaced by another terminal device.

The following describes the apparatus embodiments corresponding to the method embodiments of this application. Only a brief description of the apparatus is provided below; for specific implementation steps and details, please refer to the preceding method embodiments.

To achieve the functions of the methods provided in this application, the communication device may include hardware structures and/or software modules, implementing the aforementioned functions in the form of hardware structures, software modules, or a combination of hardware structures and software modules. Whether a particular function is implemented in the form of hardware structures, software modules, or a combination of hardware structures and software modules depends on the specific application and design constraints of the technical solution.

Figure 6 is a schematic block diagram of a communication device 1000 according to an embodiment of this application. The communication device 1000 includes a processor 1010 and a communication interface 1020. Optionally, the processor 1010 and the communication interface 1020 can be interconnected via a bus. The communication device 1000 can be a first device or a second device.

Optionally, the communication device 1000 may further include a memory 1040. The memory 1040 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), cache, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), synchronous dynamic random access memory (SDRAM), hard disk drive (HDD), registers, solid-state drive (SSD), or compact disc read-only memory (CD-ROM). The memory 1040 is used to store related instructions and/or data. The memory 1040 may be integrated with the processor 1010 or disposed separately.

Processor 1010 can be a general-purpose processor or a special-purpose processor. Processor 1010 may include one or more central processing units (CPUs), application processors, modem processors, graphics processors, image signal processors, digital signal processors (DSPs), video codec processors, controllers, or neural network processors. When processor 1010 is a CPU, the CPU can be a single-core CPU or a multi-core CPU. Processor 1010 can be a signal processor, a chip, or other integrated circuit capable of implementing the methods of this application, or a portion of the circuitry within the aforementioned processor, chip, or integrated circuit for processing functions. The processor in the embodiments of this application can be an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

The communication interface 1020 can be an input/output interface or an antenna. The input/output interface is used for inputting or outputting signals or data, or it can be an input/output circuit.

For example, the communication device 1000 is a first device, and the processor 1010 is configured to perform the following operations: receive a first reference signal; determine a first precoding matrix based on the first reference signal; transmit a second reference signal, which is processed by the first precoding matrix, and the second reference signal is used to estimate a first amplitude of a first channel; and receive first information on the first channel, the first information indicating the first amplitude.

For example, the communication device 1000 is a second device, and the processor 1010 is configured to perform the following operations: transmit a first reference signal for determining a first precoding matrix; receive a second reference signal processed by the first precoding matrix; estimate a first amplitude of a first channel based on the second reference signal; and transmit first information on the first channel, the first information indicating the first amplitude.

The above description is for illustrative purposes only. The communication device 1000 is responsible for executing the methods or steps related to the first or second device in the foregoing method embodiments.

In one possible implementation, the communication interface 1020 can be a transceiver. The transceiver may include a transmitter and a receiver, with the transmitter performing a transmission operation and the receiver performing a reception operation. For example, the processor 1010 is used to control the transceiver to receive and/or transmit signals.

In one possible implementation, the communication interface 1020 can also be a communication circuit, pins, input/output interfaces, bus, etc.

Communication device 1000 may include a transmitter but not a receiver. Alternatively, communication device 1000 may include a receiver but not a transmitter. Specifically, it depends on whether the above-described scheme performed by communication device 1000 includes both transmitting and receiving actions.

The above description is merely exemplary. For details, please refer to the methods illustrated in the above embodiments. The implementation of each operation in Figure 6 can also be found in the corresponding description of the method embodiments shown in Figure 5.

For example, the communication device 1000 can be used to execute the scheme shown in Figure 5.

For example, the communication device 1000 is a first device, the communication interface 1020 can be used to receive a first reference signal; the processor 1010 is used to determine a first precoding matrix based on the first reference signal; the communication interface 1020 is used to send a second reference signal; and the communication interface 1020 is used to receive first information on a first channel.

For example, the communication device 1000 is a second device, and the communication interface 1020 can be used to transmit a first reference signal; the communication interface 1020 is used to receive a second reference signal; the processor 1010 is used to estimate a first amplitude of a first channel based on the second reference signal; and the communication interface 1020 can be used to transmit first information on the first channel.

For details on other implementation methods, please refer to the detailed description of the embodiment shown in Figure 5 above, which will not be repeated here. It should be understood that the specific processes by which each component performs the corresponding processes described above have been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

Figure 7 is a schematic block diagram of another communication device 1100 according to an embodiment of this application. The communication device 1100 can be a first device or a second device, or it can be a chip or module in the first device or the second device, used to implement the method involved in the embodiment shown in Figure 5. Please refer to the relevant description in the above method embodiments for details.

The communication device 1100 includes a transceiver unit 1110. The transceiver unit 1110 will be described exemplarily below.

The transceiver unit 1110 may include a sending unit and a receiving unit. The sending unit is used to perform the sending action of the communication device, and the receiving unit is used to perform the receiving action of the communication device. For ease of description, the sending unit and the receiving unit are combined into one transceiver unit in this embodiment. This will be explained uniformly here and will not be repeated later. The transceiver unit 1110 can implement the corresponding communication functions. The transceiver unit 1110 may also be referred to as a communication interface or a communication module.

The communication device 1100 may include a transmitting unit but not a receiving unit. Alternatively, the communication device 1100 may include a receiving unit but not a transmitting unit. Specifically, it depends on whether the above-described scheme performed by the communication device 1100 includes both transmitting and receiving actions.

For example, the transceiver unit 1110 is used to receive a first reference signal, etc.

Optionally, the communication device 1100 may further include a processing unit 1120, which is used to perform the processing, coordination and other steps involved in the communication device 1100.

For example, the transceiver unit 1110 is used to transmit a first reference signal, etc.

Optionally, the communication device 1100 may further include a processing unit 1120, which is used to perform the processing, coordination and other steps involved in the communication device 1100.

The above description is for illustrative purposes only. The communication device 1100 will be responsible for executing the relevant methods or steps in the foregoing method embodiments.

Optionally, the communication device 1100 further includes a storage unit 1130 for storing programs or code for executing the aforementioned methods. Alternatively, the storage unit 1130 can store instructions and/or data, and the processing unit 1120 can read the instructions and/or data from the storage unit 1130 to enable the communication device 1100 to implement the aforementioned method embodiments. For example, the communication device 1100 can be used to execute the scheme shown in FIG5.

For example, the transceiver unit 1110 can be used to receive a first reference signal; the processing unit 1120 can be used to determine a first precoding matrix based on the first reference signal; the transceiver unit 1110 can be used to transmit a second reference signal, which is processed by the first precoding matrix, and the second reference signal is used to estimate a first amplitude of the first channel; the transceiver unit 1110 can be used to receive first information on the first channel, and the first information indicates the first amplitude.

For example, transceiver unit 1110 can be used to transmit a first reference signal for determining a first precoding matrix; transceiver unit 1110 can be used to receive a second reference signal processed by the first precoding matrix; processing unit 1120 can be used to estimate a first amplitude of a first channel based on the second reference signal; transceiver unit 1110 can be used to transmit first information on the first channel, the first information indicating the first amplitude.

For details on other implementation methods, please refer to the detailed description of the embodiment shown in Figure 5 above, which will not be repeated here. It should be understood that the specific processes by which each component performs the corresponding processes described above have been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

When the communication device 1000 in Figure 6 is a chip, the communication interface 1020 can be a transceiver, input/output circuit, or communication interface of the chip. The processor 1010 can be a processor integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the transmitting operation of the first or second device can be understood as the output of the chip, and the receiving operation of the first or second device in the above method embodiments can be understood as the input of the chip.

When the communication device 1100 in Figure 7 is a chip, the transceiver unit 1110 can be the transceiver, input/output circuit, or communication interface of the chip. The processing unit 1120 can be a processor, microprocessor, or integrated circuit integrated on the chip. The transmitting operation of the first or second device in the above method embodiments can be understood as the output of the chip, and the receiving operation of the first or second device in the above method embodiments can be understood as the input of the chip.

This application also provides a chip, including a processor, for calling and executing instructions stored in a memory, causing a communication device on which the chip is mounted to perform the methods in the examples above.

This application also provides another chip, including: an input interface, an output interface, and a processor, wherein the input interface, the output interface, and the processor are connected via an internal connection path, and the processor is used to execute code in a memory. When the code is executed, the processor is used to perform the methods in the examples described above. Optionally, the chip further includes a memory for storing computer programs or code.

This application also provides a processor for coupling with a memory, for performing the methods and functions related to the communication device in any of the above embodiments, or for performing the methods and functions related to the first or second device in any of the above embodiments.

In another embodiment of this application, a computer program product comprising a computer program or instructions is provided, which, when run, enables the implementation of the methods described in the foregoing embodiments.

This application also provides a computer program that, when run, enables the implementation of the methods described in the foregoing embodiments.

In another embodiment of this application, a computer-readable storage medium is provided, which stores a computer program that, when run, implements the methods described in the foregoing embodiments.

This application also provides a communication system, which includes a first device and a second device. The first device and the second device are respectively used to perform the methods performed by the first device and the second device in the foregoing embodiments.

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

Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

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

In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

Claims (33)

A communication method, characterized in that the method includes: Receive the first reference signal; Determine the first precoding matrix based on the first reference signal; A second reference signal is transmitted, which is processed by the first precoding matrix, and the second reference signal is used to estimate the first amplitude of the first channel; Receive first information on the first channel, the first information indicating the first amplitude. The method according to claim 1, characterized in that determining the first precoding matrix based on the first reference signal includes: Based on the first reference signal, the first Doppler frequency of the first channel is estimated, the first channel includes a first path, and the first Doppler frequency is the Doppler frequency of the first path. The first precoding matrix is determined based on the first Doppler frequency. The method according to claim 1, characterized in that determining the first precoding matrix based on the first reference signal includes: Based on the first reference signal, the first Doppler frequency and the second Doppler frequency of the first channel are estimated. The first channel includes a first path and a second path. The first Doppler frequency is the Doppler frequency of the first path, and the second Doppler frequency is the Doppler frequency of the second path. The first precoding matrix is determined based on the first Doppler frequency and the second Doppler frequency. The method according to claim 2, characterized in that, Before determining the first precoding matrix based on the first Doppler frequency, the method includes: obtaining first angular time delay domain information of the first path based on the first reference signal; Determining the first precoding matrix based on the first Doppler frequency includes: determining the first precoding matrix based on the first Doppler frequency and the first angular time delay domain information. The method according to claim 3, characterized in that, Before determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency, the method includes: obtaining first angular delay domain information of the first path and second angular delay domain information of the second path based on the first reference signal; Determining the first precoding matrix based on the first Doppler frequency and the second Doppler frequency includes: determining the first precoding matrix based on the first Doppler frequency, the first angular delay domain information, the second Doppler frequency, and the second angular delay domain information. The method according to claim 4, wherein the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second matrix indicates the first angular delay domain information. According to the method of claim 5, the first precoding matrix is determined based on a first matrix and a second matrix, wherein the first matrix indicates the first Doppler frequency and the second Doppler frequency, and the second matrix indicates the first angular delay domain information and the second angular delay domain information. According to the method of claim 6, the first channel comprises S paths, where S is a positive integer greater than or equal to 1, and the first precoding matrix F satisfies:
F = ( D T) -1 (E T ) -1 ;
D＝[d 1 ,…,d i ,…,d S ];
Where i and j are integers, 1≤i≤S, 1≤j≤S; (E T ) -1 is the first matrix, e j is the first Doppler frequency; (D T ) -1 is the second matrix, d i is the first angle time delay domain information; "T" indicates matrix transpose, and "-1" indicates matrix inversion. The method according to any one of claims 1 to 8 is characterized in that the first information includes a first identifier and a first amplitude, the first amplitude being the amplitude of a first path, and the first path being the path corresponding to the first identifier. According to the method of claim 9, the first information includes a second identifier and a second amplitude, the second amplitude being the amplitude of a second path, and the second path being the path corresponding to the second identifier. The method according to any one of claims 1 to 8, wherein the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of a first path, and the first identifier indicating the first path. The method according to claim 11, wherein the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path. The method according to any one of claims 1 to 12, wherein the first information indicates the first amplitude, includes: the first information indicating the first amplitude and the second amplitude of the first channel. The method according to claim 13, characterized in that, after receiving the first information on the first channel, the method includes: First data is sent, which has been processed by a second precoding matrix, which is determined based on the first amplitude and the second amplitude. The method according to any one of claims 1 to 12, characterized in that, after receiving the first information on the first channel, the method includes: First data is sent, which has been processed by a second precoding matrix, which is determined based on the first amplitude. The method according to any one of claims 1 to 15, wherein the first reference signal includes a sounding reference signal SRS, and the second reference signal includes a channel state information reference signal CSI-RS. A communication method, characterized in that the method includes: A first reference signal is sent, which is used to determine a first precoding matrix; Receive a second reference signal, which has been processed by the first precoding matrix; Based on the second reference signal, estimate the first amplitude of the first channel; First information is transmitted on the first channel, the first information indicating the first amplitude. The method according to claim 17, wherein the first reference signal is used to estimate the first Doppler frequency of the first channel, the first channel includes a first path, the first Doppler frequency is the Doppler frequency of the first path, and the first Doppler frequency is used to determine the first precoding matrix. The method according to claim 18, wherein the first reference signal is used to estimate the second Doppler frequency of the first channel, the first channel includes a second path, the second Doppler frequency is the Doppler frequency of the second path, and the second Doppler frequency is used to determine the first precoding matrix. The method according to any one of claims 17 to 19, wherein the first information includes a first identifier and a first amplitude, the first amplitude being the amplitude of a first diameter, and the first diameter being the diameter corresponding to the first identifier. According to the method of claim 20, the first information includes a second identifier and a second amplitude, the second amplitude being the amplitude of a second path, and the second path being the path corresponding to the second identifier. The method according to any one of claims 17 to 19, characterized in that the first information includes a first identifier and a first index, the first index indicating the first amplitude, the first amplitude being the amplitude of the first path, and the first identifier indicating the first path. The method according to claim 22, wherein the first information includes a second identifier and a second index, the second index indicating a second amplitude, the second amplitude being the amplitude of a second path, and the second identifier indicating the second path. The method according to any one of claims 17 to 23, wherein the first information indicates the first amplitude, comprising: the first information indicating the first amplitude and a second amplitude of the first channel. The method according to claim 24, characterized in that, after transmitting the first information on the first channel, the method includes: Receive first data, which has been processed by a second precoding matrix, which is determined based on the first amplitude and the second amplitude. The method according to any one of claims 17 to 23, characterized in that, after transmitting the first information on the first channel, the method comprises: Receive first data, which has been processed by a second precoding matrix, which is determined based on the first amplitude. The method according to any one of claims 17 to 26, wherein the first reference signal includes a sounding reference signal SRS, and the second reference signal includes a channel state information reference signal CSI-RS. A communication device, characterized in that it includes a module for implementing the method as described in any one of claims 1 to 16. The communication device according to claim 28, wherein the communication device comprises a network device or a chip. A communication device, characterized in that it includes a module for implementing the method as described in any one of claims 17 to 27. The communication device according to claim 30 is characterized in that the communication device includes a terminal device or a chip. A computer-readable storage medium, characterized in that a computer program or instructions are stored on the computer-readable storage medium, which, when the computer program or the instructions are executed, causes the method of any one of claims 1 to 16 to be implemented, or causes the method of any one of claims 17 to 27 to be implemented. A computer program, characterized in that it includes computer instructions, which, when executed, cause the method as described in any one of claims 1 to 16 to be implemented, or cause the method as described in any one of claims 17 to 27 to be implemented.