Communication method and apparatus

Abstract

A communication method and an apparatus, relating to the technical field of communications. In the method, an access network apparatus assists a terminal in performing reciprocity calibration (that is, the access network apparatus sends first indication information to the terminal), and an interval between a moment at which the access network apparatus sends the first indication information to the terminal and a moment at which the access network apparatus issues a reference signal for the terminal to measure a receive phase difference is limited to be not greater than a first time threshold, so that channel reciprocity correction between antenna ports of the terminal can be implemented.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202510150558.6, filed on February 10, 2025, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0003] In communication systems, estimating the quality of the uplink or downlink channel is crucial for improving data transmission performance. For communication systems supporting Time Division Duplex (TDD), the uplink and downlink channels possess equivalence, also known as uplink-downlink channel reciprocity. Uplink-downlink channel reciprocity means that the path loss, delay, or phase of the uplink and downlink channels are identical. Utilizing uplink-downlink channel reciprocity, a terminal can use downlink channel information obtained by measuring the channel state information-reference signal (CSI-RS) as uplink channel information. However, in real-world communication environments, due to hardware differences, interference, and other factors, uplink-downlink channel reciprocity may not hold true. This leads to a discrepancy between the uplink channel information determined by the terminal based on downlink channel information and the actual uplink channel information. Therefore, how to achieve uplink-downlink reciprocity correction for the terminal has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a communication method and apparatus that can realize uplink and downlink reciprocity correction of a terminal.

[0005] The present application is described below from different aspects. It should be understood that the different implementation methods and beneficial effects described below can be referenced from each other.

[0006] Firstly, this application provides a communication method that can be applied to a terminal-side communication device, such as a terminal or a communication module / processing module within a terminal, or a circuit or chip in the terminal responsible for communication functions (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip), or a circuit or chip in the terminal responsible for processing functions (such as a graphics processing unit (GPU), an artificial intelligence (AI) processor, or an application-specific integrated circuit (ASIC)). Taking the application of this method to a terminal as an example, in this method, the terminal receives first indication information, which indicates N-1 transmission phase differences between the terminal's N-1 antenna ports and a reference antenna port, respectively. The terminal includes N antenna ports, which include the N-1 antenna ports and the reference antenna port, where N is an integer greater than 1. The terminal receives a downlink reference signal, which is used to determine N-1 receive phase differences between the N-1 antenna ports and the reference antenna port, respectively. The time interval between the reception time of the first indication information and the reception time of the downlink reference signal is less than or equal to a first time threshold. The N-1 transmit phase differences and the N-1 receive phase differences are used for transmit phase compensation of the terminal's antenna ports.

[0007] In this embodiment, the execution order of the terminal receiving the first indication information and receiving the downlink reference signal is not limited. For example, receiving the first indication information and receiving the downlink reference signal can be performed simultaneously, or the access network device can send the first indication information first and then send the downlink reference signal (correspondingly, the terminal receives the first indication information first and then the downlink reference signal), or the access network device can send the downlink reference signal first and then send the first indication information (correspondingly, the terminal receives the downlink reference signal first and then the first indication information). Specifically, this embodiment assists the terminal in performing reciprocity calibration through the access network device (i.e., the access network device sends the first indication information to the terminal), and limits the interval between the time when the access network device sends the first indication information to the terminal and the time when the access network device sends the reference signal for the terminal to measure the received phase difference to not exceed a first time threshold, thereby realizing channel reciprocity correction between the antenna ports of the terminal. The reason for limiting the time interval between the access network device sending the first indication information to the terminal and the time the access network device sends the reference signal for the terminal to measure the received phase difference to no greater than a first time threshold is that if the first time threshold is exceeded, the transmitted phase difference and the received phase difference may no longer be correlated, thus failing to support uplink and downlink reciprocity correction. In other words, by limiting the time interval between the access network device sending the first indication information to the terminal and the time the access network device sends the reference signal for the terminal to measure the received phase difference to no greater than a first time threshold, this application is beneficial to improving the availability / feasibility of channel reciprocity compensation.

[0008] In one possible implementation, before receiving the first indication information, the method further includes:

[0009] A first uplink reference signal is transmitted, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, respectively.

[0010] In this implementation, the terminal uses a first uplink reference signal to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, which is easy to implement.

[0011] In one possible implementation, when the first downlink reference signal is transmitted aperiodically, the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal is less than or equal to a second time threshold.

[0012] In this implementation, by limiting the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal to be less than or equal to the second time threshold, the availability / feasibility of channel reciprocity compensation can also be improved.

[0013] In one possible implementation, the second time threshold is greater than or equal to 1 ms. Typically, the duration of the second time threshold can be represented by the number of symbols; for example, when the subcarrier spacing is 15 kHz, the second time threshold is greater than or equal to 14 symbols; when the subcarrier spacing is 30 kHz, the second time threshold is greater than or equal to 28 symbols.

[0014] In this implementation, a time range for the second time threshold is defined. This phase difference notification, which is completed under a given time threshold, helps to improve the availability / feasibility of channel reciprocity compensation.

[0015] In one possible implementation, the N antenna ports used to receive the downlink reference signal are the same as the N antenna ports used to transmit the first uplink reference signal.

[0016] It should be noted that, in this embodiment, the terminal's transmit phase difference includes the transmit antenna port phase difference δT caused by the terminal's hardware factors and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. Similarly, the terminal's receive phase difference also includes the receive antenna port phase difference δR caused by the terminal's hardware factors and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. To eliminate the influence of δH, in this embodiment, the access network device can use the same antenna port as the one used to receive the first uplink reference signal to transmit the downlink reference signal, thereby ensuring the relative relationship of δH between antenna ports. That is, for the access network device, the antenna port used by the access network device to transmit the downlink reference signal (e.g., CSI-RS) is the same as the antenna port used by the access network device to receive the first uplink reference signal (e.g., AS SRS). Correspondingly, for the terminal, the antenna port used by the terminal to receive the downlink reference signal is the same as the antenna port used by the terminal to transmit the first uplink reference signal. This can eliminate the influence of δH on the transmit or receive phase difference.

[0017] In one possible implementation, the first indication information is carried in a first message, which includes any of the following: a radio resource control (RRC) message, a medium access control control element (MAC CE), or downlink control information (DCI).

[0018] This implementation method offers high operability by carrying the first indication information in an RRC message, MAC CE, or DCI.

[0019] In one possible implementation, the N-1 transmission phase differences include a first transmission phase difference, which is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports; the first transmission phase difference is carried by multiple bits in the first message, for example by 4 bits or 5 bits in the first message, which is beneficial for protocol compatibility.

[0020] In one possible implementation, after receiving the first indication information, the method further includes:

[0021] A second uplink reference signal is transmitted, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

[0022] In this implementation, the non-codebook-based probe reference signal or the beamformed probe reference signal serves as the phase-compensated uplink reference signal, which will be referred to as the second uplink reference signal for ease of distinction. It should be understood that phase compensation during the transmission of the second uplink reference signal ensures that the terminal's transmit phase difference equals its receive phase difference (or that the phase difference between the terminal's transmit antenna port and receive antenna port equals the phase difference between the terminal's receive antenna port). This improves the matching between the precoding and the actual uplink channel information when using downlink channel information as uplink channel information for precoding, thereby enhancing the accuracy of precoding and transmission performance.

[0023] In one possible implementation, after receiving the first indication information, the method further includes:

[0024] Based on the N-1 transmit phase differences and the N-1 receive phase differences, determine the N-1 phase difference compensation values ​​between the N-1 antenna ports and the reference antenna port respectively;

[0025] The second uplink reference signal is sent based on the N-1 phase difference compensation values.

[0026] In this implementation, when the time interval between the reception time of the first indication information and the reception time of the downlink reference signal is less than or equal to the first time threshold, since the correlation between the N-1 transmission phase differences and the N-1 reception phase differences is strong at this time, the N-1 phase difference compensation values ​​between the N-1 antenna ports and the reference antenna port can be determined based on the N-1 transmission phase differences and the N-1 reception phase differences. Then, when transmitting the second uplink reference signal, the N-1 phase difference compensation values ​​can be used to perform phase compensation on the transmission phase of the N-1 antenna ports of the terminal, so that the transmission phase difference of the terminal is equal to the reception phase difference of the terminal (or the phase difference of the transmitting antenna port of the terminal is equal to the phase difference of the receiving antenna port of the terminal). This improves the matching between the precoding and the actual uplink channel information when using downlink channel information as uplink channel information for precoding transmission, thereby improving the accuracy of precoding and transmission performance.

[0027] In one possible implementation, the first time threshold is 1 ms or 2 ms. Typically, the duration of the first time threshold can be represented by the number of symbols. For example, with a first time threshold of 1 ms, when the subcarrier spacing is 15 kHz, the first time threshold is 14 symbols; when the subcarrier spacing is 30 kHz, the first time threshold is 28 symbols. As another example, with a first time threshold of 2 ms, when the subcarrier spacing is 15 kHz, the first time threshold is 28 symbols; when the subcarrier spacing is 30 kHz, the first time threshold is 56 symbols.

[0028] In this implementation, a time range for the first time threshold is defined. This phase difference notification, which is completed under a given time threshold, helps to improve the availability / feasibility of channel reciprocity compensation.

[0029] Secondly, this application provides a communication method that can be applied to network-side communication devices, such as network-side access network devices, modules (e.g., circuits, chips, or chip systems) within the access network device, or logic nodes, logic modules, or software capable of implementing all or part of the functions of the access network device. Taking the application of this method to an access network device as an example, in this method, the access network device sends first indication information, which indicates N-1 transmission phase differences between N-1 antenna ports of a terminal and a reference antenna port, respectively. The terminal includes N antenna ports, which include the N-1 antenna ports and the reference antenna port, where N is an integer greater than 1. The access network device sends a downlink reference signal, which is used to determine N-1 reception phase differences between the N-1 antenna ports and the reference antenna port, respectively. The time interval between the transmission time of the first indication information and the transmission time of the downlink reference signal is less than or equal to a first time threshold. The N-1 transmission phase differences and the N-1 reception phase differences are used for transmission phase compensation of the antenna ports of the terminal.

[0030] In one possible implementation, before sending the first indication information, the method further includes:

[0031] A first uplink reference signal is received, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, respectively.

[0032] In one possible implementation, when the first downlink reference signal is transmitted aperiodically, the time interval between the reception time of the first uplink reference signal and the transmission time of the downlink reference signal is less than or equal to a second time threshold.

[0033] In one possible implementation, the second time threshold is greater than or equal to 1 ms.

[0034] In one possible implementation, the N antenna ports of the access network device used to transmit the downlink reference signal are the same as the N antenna ports of the access network device used to receive the first uplink reference signal.

[0035] In one possible implementation, the first indication information is carried in a first message, which includes any of the following: an RRC message, a MAC CE, or a DCI.

[0036] In one possible implementation, the N-1 transmission phase differences include a first transmission phase difference, which is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports; the first transmission phase difference is carried by multiple bits in the first message.

[0037] In one possible implementation, after sending the first indication information, the method further includes:

[0038] Receive a second uplink reference signal, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

[0039] In one possible implementation, the first time threshold is 1ms or 2ms.

[0040] Thirdly, this application provides a communication device comprising units, modules, or means for implementing any of the methods in the first to second aspects, or any possible implementations of any of the aspects, wherein the modules, units, or means may be implemented by software, by hardware, or by a combination of software and hardware.

[0041] Fourthly, this application provides a communication device including a processor. The processor is configured to cause the communication device to implement the methods shown in any of the first to second aspects, or any possible implementation thereof.

[0042] Optionally, the communication device further includes a transceiver for sending and receiving information.

[0043] Optionally, the communication device further includes a memory storing a computer program; the processor and transceiver are used to invoke the computer program in the memory, causing the communication device to implement the method shown in any of the first or second aspects, or any possible implementation thereof.

[0044] In one possible design, the communication device can be a chip that implements the above method or a device containing a chip.

[0045] Fifthly, this application provides a communication device comprising one or more processors, which implement, via logic circuits or execution code instructions, any of the methods described in the first or second aspects, or any possible implementation thereof.

[0046] Optionally, the communication device further includes an interface circuit for receiving signals from other communication devices outside the communication device and transmitting them to the processor, or sending signals from the processor to other communication devices outside the communication device.

[0047] Optionally, the communication device may further include a memory for storing part or all of the computer programs or instructions necessary to implement the functions involved in the first aspect above.

[0048] The aforementioned communication device may be a terminal, a communication module in a terminal, or a chip in a terminal that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0049] The aforementioned communication device may be an access network device, a module (e.g., a circuit, chip, or chip system) within the access network device, or a logic node, logic module, or software capable of implementing all or part of the functions of the access network device.

[0050] Sixthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer, implement the method shown in any of the first to second aspects, or any possible implementation thereof.

[0051] In a seventh aspect, this application provides a computer program product, including computer program code, which, when read and executed by a computer, causes the computer to perform any of the methods in the first aspect to the second aspect, or any possible implementation thereof.

[0052] Eighthly, this application provides a chip system including at least one processor and an interface, the processor being configured to read and execute a computer program or instructions in a memory, wherein when the computer program or instructions are executed, the chip performs the method as described in any one of the first or second aspects, or the method shown in any possible implementation of either aspect.

[0053] Ninthly, this application provides a communication system that may include a terminal and an access network device. The terminal is used to perform the method shown in the first aspect or any possible implementation thereof. The access network device is used to perform the method shown in the second aspect or any possible implementation thereof. Attached Figure Description

[0054] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0055] Figure 2 is a schematic diagram of the architecture of the O-RAN system provided in this application;

[0056] Figure 3 is a schematic diagram of the network element function division and protocol layer structure of an O-RAN device provided in this application;

[0057] Figure 4-a is a flowchart illustrating the non-codebook uplink transmission mode provided in this application;

[0058] Figure 4-b is a schematic diagram of the transmission phase difference and reception phase difference of the terminal provided in this application;

[0059] Figure 5 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0060] Figure 6 is a schematic diagram of the application scenario of uplink and downlink reciprocity correction of the terminal provided in the embodiment of this application;

[0061] Figure 7 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0062] Figure 8 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0063] Figure 9 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application. Detailed Implementation

[0064] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0065] In the description of this application, terms such as "first" and "second" are used only to distinguish different objects, not to describe a specific order. Furthermore, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document 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 alone, A and B simultaneously, and B alone. Additionally, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0066] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0067] In this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0068] It is understood that in this application, "when," "if," and "if" all refer to the device making a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to make a judgment when it is implemented, nor do they imply any other limitations.

[0069] In this application, the use of singular pronouns for elements is intended to indicate "one or more," rather than "one and only one," unless otherwise specified. The terms "system" and "network" in the embodiments of this application are used interchangeably.

[0070] It is understood that in the embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. Determining B based on A does not mean that B can be determined solely based on A; B can also be determined based on A and / or other information.

[0071] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0072] The technical solutions of the embodiments of this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, and LTE Time Division Duplex (TDD) systems. The technical solutions of the embodiments of this application can also be applied to other communication systems, such as Public Land Mobile Network (PLMN) systems, LTE Advanced (LTE-A) systems, the 5th generation (5G) systems, New Radio (NR) systems, Machine-to-Machine (M2M) systems, or other future communication systems, or other wireless communication systems employing wireless access technologies, all of which can adopt the technical solutions of the embodiments of this application.

[0073] Please refer to Figure 1, which is a schematic diagram of the architecture of the communication system applied in the embodiments of this application. It should be noted that Figure 1 is a possible, non-limiting system schematic diagram. As shown in Figure 1, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 10 may also include an Internet 300. RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal (120a-120j in Figure 1, collectively referred to as 120). RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). Terminal 120 is wirelessly connected to RAN node 110. RAN node 110 is connected to core network 200 wirelessly or via a wired connection. The core network elements in core network 200 and RAN nodes 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions, or they can be a single physical device integrating some core network element functions and some RAN node 110 functions. Terminals can be interconnected with each other, and RAN nodes 110 can be interconnected with each other via wired or wireless means. Figure 1 is only a schematic diagram. This communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices. Each device may also include different functional units, which are not shown in Figure 1.

[0074] RAN 100 can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication systems, or future-oriented evolution systems. RAN 100 can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0075] RAN node 110, sometimes also referred to as a radio access network device, access network apparatus, RAN entity, or access node, constitutes part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station. For terminals 120j accessing RAN 100 through network element 120i, network element 120i is a base station; but for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes both referred to as communication devices. For example, network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and network elements 120a-120j can be understood as communication devices with terminal functions.

[0076] In one possible scenario, RAN node 110 can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system. RAN node 110 can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, RAN node 110 can also be a server, a wearable device, a vehicle, or an in-vehicle device. For example, the access network device in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of RAN node 110 in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). In this application, RAN node 110 can also be a logical node, logical module, or software that can implement all or part of the functions of RAN node 110.

[0077] In another possible scenario, multiple RAN nodes 110 collaborate to assist the terminal in achieving wireless access, with each RAN node 110 implementing a portion of the base station's functions. For example, a RAN node 110 can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0078] 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 ORAN 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 and hardware modules.

[0079] For example, please refer to Figure 2, which is a schematic diagram of the architecture of the O-RAN system provided in this application. Figure 2 is only a schematic diagram, and the O-RAN system may also include other components besides those shown in Figure 2. As shown in Figure 2, the access network device (e.g., it may be an eNB, gNB, or next-generation access network device) communicates with the core network elements in the CN through a backhaul link and communicates with the terminal through the air interface.

[0080] Specifically, the BBU in the access network device communicates with the core network elements in the CN via a backhaul link, and the RU in the access network device communicates with at least one terminal via an air interface. The BBU communicates with at least one RU via a fronthaul link. The BBU and RU may or may not be co-located. The BBU includes at least one CU and at least one DU, which can communicate via at least one midhaul link.

[0081] Figure 3 illustrates a schematic diagram of the network element function division and protocol layer structure of an O-RAN device. In some examples, the CU is a logical node carrying the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, and other control functions of the access network device. The CU connects to network nodes such as the core network through interfaces, which can be interfaces such as E2 interfaces. Optionally, the CU can have some of the functions of the core network. The CU (e.g., the PDCP layer and higher layers) connects to the DU (e.g., the RLC layer and lower layers) through interfaces, which can be interfaces such as F1 interfaces. In some examples, these interfaces (e.g., the F1 interface) can provide control plane (C-Plane) and user plane (U-Plane) functions (e.g., interface management, system information management, UE context management, RRC message transmission, etc.). F1AP is the application protocol of the F1 interface, and in some examples, it defines the signaling procedures of F1. The F1 interface supports the control plane F1-C and the user plane F1-U.

[0082] In some examples, the CU can be split into CU-CP (control unit-control plane) and CU-UP (control unit-user plane). CU-CP is a logical node carrying the RRC layer and PDCP-C (control plane part of PDCP) layer, used to implement the CU's control plane functions. CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements in the core network can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. The AMF network element is responsible for mobility management in the mobile network, such as terminal location updates, terminal registration with the network, and terminal handover. CU-UP is a logical node carrying the SDAP layer and PDCP-U (user plane part of PDCP) layer, used to implement the CU's user plane functions. CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements in the core network, such as the user plane function (UPF) in a 5G system, are responsible for data forwarding and receiving in the terminal. The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0083] In some examples, a DU is a logical node that carries the radio link control (RLC) layer, medium access control (MAC) layer, higher physical layer (Higher PHY) layer, and other functions. In some examples, a DU can control at least one RU. The DU connects to the RU through interfaces, which can be fronthaul interfaces. In some examples, the Higher PHY layer includes the physical (PHY) layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0084] In some examples, the RU is a logical node that carries both lower physical layer (PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP transmission reception point (TRP), a remote radio head (RRH), or other similar entities. In some examples, the Low-PHY includes PHY processing functions such as Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more terminals via a wireless link.

[0085] The DU and RU can be co-located or not. The DU and RU exchange control plane and user plane information via a fronthaul link through the Lower-Layer Split CUS-Plane (LLS-CUS) interface. LLS-CUS may include LLS-C and LLS-U interfaces providing the control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and RU. The DU and RU exchange management information via an LLS-M interface on the fronthaul link; the management plane (M-Plane) refers to non-real-time management operations between the DU and RU.

[0086] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0087] A terminal is a device or module that connects to the aforementioned communication system and possesses corresponding communication functions. Terminals can also be referred to as terminal equipment, user equipment (UE), user devices, access terminals, user units, user stations, mobile stations, mobile stations (MS), remote stations, remote terminals, mobile devices, user terminals, terminal units, terminal stations, terminal devices, wireless communication equipment, user agents, or user devices, etc. Terminals typically contain communication modules, circuits, or chips that perform the corresponding communication functions. They can also be configured with program instructions for performing these functions. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, transportation vehicle with wireless communication function, communication module, roadside unit (RSU) with terminal function, etc. The embodiments of this application do not limit the device form of the terminal.

[0088] For ease of description, the following description uses a base station as an example of RAN node 110. Base stations and terminals can be fixed or mobile. Base stations and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0089] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0090] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0091] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0092] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also susceptible to interference from signals from neighboring cells.

[0093] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "base station sending information" can be understood as the base station sending information to another device (such as a terminal), or it can be understood as logical module 1 in the base station sending information to logical module 2 in the base station.

[0094] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "base station receiving information" can be understood as the base station receiving information from another device (such as a terminal), or it can be understood as logical module 1 in the base station receiving information from logical module 2 in the base station.

[0095] The communication between different devices involved in this application can refer to direct communication between different devices (i.e., without the need for relaying or forwarding by other devices), or communication between different devices through other devices (i.e., requiring relaying or forwarding by other devices), or communication between a functional unit within a device and other devices through another functional unit. In other words, "sending information to… (e.g., a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the destination of the information being the terminal. This can include sending information directly or indirectly to the terminal. "Receiving information from… (e.g., a terminal)" or "receiving information from… (e.g., a terminal)" or "receiving information sent (e.g., by a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the source of the information being the terminal. This can include receiving information directly or indirectly from the terminal. Information may undergo necessary processing between the source and destination, such as format changes, analog-to-digital conversion, amplification, filtering, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be elaborated further here.

[0096] To facilitate understanding of the embodiments of this application, some knowledge / terms used in the solutions of this application are introduced below. It should be noted that these explanations are for the purpose of making the embodiments of this application easier to understand, and should not be regarded as limiting the scope of protection claimed by this application.

[0097] 1. Antenna Port

[0098] An antenna port can be simply referred to as a port. It can be understood as a transmitting antenna that is recognized by the receiving device, or a spatially distinguishable transmitting antenna. Each virtual antenna can be pre-configured with one antenna port. Each virtual antenna can be a weighted combination of multiple physical antennas. Each antenna port can correspond to a reference signal; therefore, each antenna port can be called a reference signal port, such as a sounding reference signal (SRS) port or a CSI-RS port. Depending on the equipment to which the transmitting antenna belongs, antenna ports include the antenna ports of a terminal or the antenna ports of an access network device. Specifically, an SRS port is the antenna port of a terminal, and a CSI-RS port is the antenna port of a base station. Optionally, an SRS port can also be understood as an antenna port for transmitting SRS, and a CSI-RS port can also be understood as an antenna port for transmitting CSI-RS.

[0099] 2. Uplink and downlink channel reciprocity

[0100] Because electromagnetic wave propagation is reversible, in scenarios where uplink and downlink (referred to as uplink and downlink) operate on the same frequency band and from the same transceiver antenna, the uplink and downlink channels possess equivalence characteristics: that is, path loss, delay, and phase are the same for both uplink and downlink. Ideally, By utilizing reciprocity, a base station can obtain downlink channel information from an uplink reference signal (e.g., SRS) sent by a terminal, thereby performing downlink scheduling. Alternatively, by utilizing reciprocity, a terminal can obtain uplink channel information from a downlink reference signal (e.g., CSI-RS) sent by a base station. In the embodiments of this application, uplink and downlink channel reciprocity can be simply referred to as channel reciprocity, reciprocity, etc.

[0101] 3. Reciprocity correction

[0102] In a communication system, the channel amplitude and phase experienced by a signal from its generation to its acquisition by the receiver are jointly determined by the "UE-side hardware + radio path response + base station-side hardware": the uplink signal generated by the UE will experience a multiplicative factor when transmitted from the UE side to the transmission medium (air). After the signal undergoes the uplink channel response, it will experience a multiplicative coefficient at the base station side. The downlink signal generated by the base station will undergo a multiplicative coefficient when it is transmitted to the transmission medium from the base station side. After experiencing the downlink channel response, a multiplicative factor will be applied on the UE side. As can be seen from the reciprocity principle, the uplink and downlink channel responses can be... It can be obtained by direct transformation, but if and Unlike other channels, the uplink and downlink channels will not be reciprocal, meaning there will be deviations in amplitude and phase between the uplink and downlink channels. This makes it impossible to directly obtain the downlink channel response from the uplink channel response. Similarly, and Differences can also lead to a lack of reciprocity in the channel. To ensure reciprocity between uplink and downlink channels, both the UE and the base station need to perform reciprocity corrections separately to guarantee reciprocity. and Same and and The same applies. The embodiments of this application mainly involve the reciprocity correction of terminals.

[0103] Generally, channel reciprocity requires high time synchronization. Uplink and downlink reciprocity are contingent upon the time interval between uplink and downlink time slots being less than the channel's coherence time. If time synchronization is inaccurate, or if the channel changes too rapidly due to factors such as the high speed of the mobile terminal, exceeding the coherence time range, uplink and downlink channel reciprocity will be compromised. For example, using 5G communication on a high-speed train can lead to uplink and downlink reciprocity failure due to the rapid channel changes caused by the train's high speed. Furthermore, channel reciprocity demands high hardware performance. To fully utilize uplink and downlink reciprocity, the radio frequency front-ends of base stations and terminals need to possess high performance, including fast signal processing capabilities and accurate phase and amplitude control. Otherwise, suboptimal hardware characteristics can also lead to inconsistencies between uplink and downlink signals, affecting the effectiveness of reciprocity utilization. In other words, in actual communication environments, due to factors such as hardware differences and interference, channel reciprocity may not be fully valid. This may cause the downlink channel information estimated by the terminal based on CSI-RS (due to channel reciprocity, the terminal can use the downlink channel information estimated based on CSI-RS as uplink channel information) to deviate from the terminal's actual uplink channel state, thereby affecting the accuracy of precoding and transmission performance.

[0104] For example, as shown in Figure 4-a, in non-codebook (NCB) uplink transmission mode, the terminal first obtains uplink channel information based on the CSI-RS sent by the base station and channel reciprocity (that is, the terminal uses the downlink channel information obtained by measuring the CSI-RS as the uplink channel information), and then calculates multiple candidate precodes. The terminal then loads these candidate precodes onto the SRS resource and sends them to the base station. Correspondingly, the base station processes and analyzes the received SRS, selects a suitable precode from the multiple candidate precodes sent by the terminal, and instructs the selected precode to the terminal via the SRS resource indicator (SRI) in the DCI. The terminal can then transmit uplink data on the physical uplink shared channel (PUSCH) according to the DCI instruction.

[0105] However, in the uplink transmission mode of NCB described above, due to hardware constraints and limitations, there may be a phase difference between the receiving antenna port and the transmitting antenna port of the terminal, and this phase difference may vary (as shown in Figure 4-b, taking a terminal with antenna port 1 and antenna port 2 as an example, due to hardware constraints, the phase difference between the receiving antenna port and the transmitting antenna port is not equal, i.e., δR≠δT). When the terminal obtains downlink channel information based on the downlink reference signal (e.g., CSI-RS), it relies on the phase difference between the receiving antenna ports (i.e., the phase difference between the receiving antenna ports). If this downlink channel information is used as uplink channel information for precoding, a mismatch between the precoding and the actual uplink channel information will occur, affecting the accuracy of precoding and transmission performance. Therefore, how to achieve uplink-downlink reciprocity correction of the terminal, thereby improving the accuracy of precoding and transmission performance, has become an urgent problem to be solved.

[0106] Based on this, this application proposes a communication method and apparatus that uses a base station to assist a terminal in performing reciprocity calibration (i.e., the base station sends phase difference indication information to the terminal), and limits the interval between the time when the base station sends the phase difference indication information to the terminal and the time when the base station sends a reference signal for the terminal to measure the received phase difference, thereby achieving channel reciprocity correction between the antenna ports of the terminal. It should be noted that the phase difference indication information will be referred to as the first indication information in the following text.

[0107] It should be noted that the phase difference of the transmitting antenna port of the terminal described in the embodiments of this application refers to the phase difference between the terminal's antenna port and the reference antenna port caused by hardware factors of the terminal's transmit link when the terminal's antenna port is used for transmitting. The phase difference of the receiving antenna port of the terminal refers to the phase difference between the terminal's antenna port and the reference antenna port caused by hardware factors of the terminal's receive link when the terminal's antenna port is used for receiving. In the following text, the phase difference of the receiving antenna port of the terminal can be expressed as δR, and the phase difference of the transmitting antenna port of the terminal can be expressed as δT. Optionally, the reference antenna port is one of the antenna ports of the terminal.

[0108] It should be noted that in the description of this application, "including" can also be replaced by "instruction" or "configuration," etc. "Instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information (such as the first instruction information below) is called the information to be instructed. In the specific implementation process, there are many ways to indicate the information to be instructed. For example, the information to be instructed can be directly indicated, including the information itself or its index. Alternatively, the information to be instructed can be indirectly indicated by indicating other information, where there is a relationship between the other information and the information to be indicated. Another example is that only a part of the information to be indicated can be indicated, while the other parts are known, pre-agreed, or deducible. Furthermore, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing the instruction overhead to some extent.

[0109] In this application, the descriptions of "message" and "signaling" can be used interchangeably; for example, an RRC message can also be called an RRC signaling.

[0110] The communication method and apparatus provided in this application will be further described below with reference to the accompanying drawings. It is understood that this application uses an access network device and a terminal as examples to illustrate the execution of the interaction, but this application does not limit the execution subject of the interaction. For example, the method executed by the access network device in this application can also be implemented by a module (e.g., a circuit, chip, or chip system) in the access network device, or a logical node, logical module, or software that can implement all or part of the functions of the access network device; the method executed by the terminal in this application can also be implemented by a communication / processing module in the terminal, or a circuit or chip (such as a modem chip (also known as a baseband chip), or a SoC chip / SIP chip containing a modem core, or a GPU / AI processor / ASIC) in the terminal responsible for communication / processing functions.

[0111] Please refer to Figure 5, which is a flowchart illustrating a communication method provided in an embodiment of this application. As shown in Figure 5, the communication method may include the following steps:

[0112] S501. The access network device sends a first instruction message to the terminal. Correspondingly, the terminal receives the first instruction message from the access network device.

[0113] The first indication information indicates the N-1 transmission phase differences between the terminal's N-1 antenna ports and the reference antenna port, respectively. The terminal includes N antenna ports, which include the aforementioned N-1 antenna ports and the aforementioned reference antenna port (or, the N antenna ports include the reference antenna port and the other N-1 antenna ports besides the reference antenna port), where N is an integer greater than 1. For example, assuming the terminal has 3 antenna ports (N=3) and these 3 antenna ports are antenna port 1, antenna port 2, and antenna port 3, and the reference antenna port is antenna port 1, the transmission phase difference between antenna port 2 and antenna port 1 is transmission phase difference 21, and the transmission phase difference between antenna port 3 and antenna port 1 is transmission phase difference 31. Therefore, the first indication information can indicate transmission phase difference 21 and transmission phase difference 31 respectively.

[0114] It should be understood that the transmission phase difference involved in the embodiments of this application mainly includes two parts: one part is the phase difference δT between the receiving antenna ports of the terminal caused by hardware factors of the terminal, and the other part is the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. That is, the transmission phase difference between any antenna port of the terminal and the reference antenna port is equal to the sum of δT and δH. Optionally, the transmission phase difference described in this application may also be referred to as the first phase difference, and the receiving phase difference may also be referred to as the second phase difference; the specific names are not limited.

[0115] Optionally, the reference antenna port may also be referred to as a reference port, etc., without limitation. For example, the reference antenna port may be predefined, such as protocol-predefined. Alternatively, the reference antenna port may be pre-configured. Alternatively, the reference antenna port may be determined by the access network device itself. Optionally, when the access network device determines the reference antenna port itself, the access network device may also send the determined reference antenna port to the terminal so that the terminal can determine the N-1 receiving phase differences between the aforementioned N-1 antenna ports and the aforementioned reference antenna port.

[0116] Optionally, the first indication information can be carried in a first message, such as an RRC message, a MAC CE, or a DCI message, etc., without limitation. Optionally, the following uses one of the N-1 transmission phase differences (for ease of description, this one transmission phase difference will be referred to as the first transmission phase difference, where the first transmission phase difference is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports) as an example to illustrate how the first indication information indicates / quantizes the transmission phase difference. Specifically, the first transmission phase difference can be carried by multiple bits in the first message, for example, x bits can be used to indicate / quantize the first transmission phase difference, where x is an integer greater than 1, such as x = 4 or x = 5. For example, the value of the first transmission phase difference can be selected from the following set of phase differences: Where M = 2 x .

[0117] For example, taking x = 4 as an example, the above set of phase differences is: Taking x=5 as an example again, the above set of phase differences is: These two specific examples demonstrate that the more bits used to carry the first transmitted phase difference, the finer the granularity of the first phase difference indication, and therefore the higher the indication accuracy. The term "invalid" indicates an invalid indication value. For example, if x = 4, there are 16 bit states. If "1111" is preset to represent "invalid," then when the value of these 4 bits is "1111," the indication value is invalid; if "0000" is preset to represent "invalid," then when the value of these 4 bits is "0000," the indication value is invalid. Similarly, if x = 5, there are 32 bit states. If "11111" is preset to represent "invalid," then when the value of these 5 bits is "11111," the indication value is invalid; if "00000" is preset to represent "invalid," then when the value of these 5 bits is "00000," the indication value is invalid.

[0118] The following describes how an access network device can determine the N-1 transmission phase differences between the N-1 antenna ports of a terminal and a reference antenna port. In one possible implementation, the access network device can determine the N-1 transmission phase differences between the N-1 antenna ports of the terminal and the reference antenna port by measuring a first uplink reference signal from the terminal. Specifically, before step S501, step S500 may also be included:

[0119] S500: The terminal sends a first uplink reference signal to the access network device. Correspondingly, the access network device receives the first uplink reference signal from the terminal.

[0120] Typically, a terminal can use N antenna ports to send a first uplink reference signal to the access network device, and correspondingly, the access network device can use N antenna ports to receive the first uplink reference signals from the terminal's N antenna ports. This first uplink reference signal is used to determine the N-1 transmission phase differences between the terminal's N-1 antenna ports and the reference antenna port. For example, the first uplink reference signal can be an antenna switching (AS) signal, abbreviated as AS SRS. Alternatively, the first uplink reference signal can also be a codebook-based (CB) signal, abbreviated as CB SRS. For ease of understanding, the following description primarily uses AS SRS as the first reference signal for illustrative purposes. For instance, by measuring the AS SRS, the access network device can determine the transmission phase difference between each antenna port of the terminal used to transmit the AS SRS and the reference antenna port.

[0121] S502. The access network device sends a downlink reference signal to the terminal. Correspondingly, the terminal receives the downlink reference signal from the access network device.

[0122] It should be noted that the timing of the access network device sending the downlink reference signal and the timing of the access network device sending the first indication information are not sequential (i.e., the execution order of steps S501 and S502 is not limited in this application embodiment). For example, the access network device may send the first indication information first and then send the downlink reference signal (or execute step S501 first and then step S502), or the access network device may send the downlink reference signal first and then send the first indication information (or execute step S502 first and then step S501), or steps S501 and S502 may be executed simultaneously. This application does not impose any limitations. The downlink reference signal can be, for example, CSI-RS, etc., and is not limited. The aforementioned downlink reference signal is used to determine the N-1 received phase differences between the N-1 antenna ports of the terminal and the reference antenna port.

[0123] In one possible implementation (1), the time interval between the reception time of the first indication information and the reception time of the downlink reference signal is less than or equal to a first time threshold (e.g., Δt1). That is, for the terminal, the time interval between the moment the terminal receives the downlink reference signal sent by the access network device and the moment the terminal receives the first indication information sent by the access network device does not exceed the first time threshold. Optionally, it can also be said that the time interval between the transmission time of the first indication information and the transmission time of the downlink reference signal is less than or equal to the first time threshold. That is, for the access network device, the time interval between the moment the access network device sends the downlink reference signal and the moment the access network device sends the first indication information does not exceed the first time threshold. Optionally, in this implementation (1), the first downlink reference signal can be periodically transmitted or semi-statically transmitted. The first time threshold is 1ms or 2ms. Generally speaking, the duration of the first time threshold can be represented by the number of symbols. For example, taking a first time threshold of 1ms as an example, when the subcarrier spacing is 15kHz, the first time threshold is 14 symbols; when the subcarrier spacing is 30kHz, the first time threshold is 28 symbols. For example, taking a first time threshold of 2ms as an example, when the subcarrier spacing is 15kHz, the first time threshold is 28 symbols; when the subcarrier spacing is 30kHz, the first time threshold is 56 symbols. Optionally, when the time interval between the reception time of the first indication information and the reception time of the downlink reference signal is greater than the first time threshold (or the time interval between the transmission time of the first indication information and the transmission time of the downlink reference signal is greater than the first time threshold), the transmission phase difference measured by the access network device may not be related to the reception phase difference determined based on the downlink reference signal, and therefore cannot be used for uplink and downlink reciprocity correction on the terminal side.

[0124] In one possible implementation (2), the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal is less than or equal to a second time threshold (e.g., Δt2). That is, for the terminal, the time interval between the moment the terminal transmits the first uplink reference signal and the moment the terminal receives the downlink reference signal transmitted by the access network device does not exceed the second time threshold. Optionally, it can also be said that the time interval between the reception time of the first uplink reference signal and the transmission time of the downlink reference signal is less than or equal to the second time threshold. That is, for the access network device, the time interval between the moment the access network device receives the first uplink reference signal transmitted by the terminal and the moment the access network device transmits the downlink reference signal is less than or equal to the second time threshold. Optionally, in this implementation (2), the first downlink reference signal can be transmitted aperiodically. The second time threshold is greater than or equal to 1ms. Generally speaking, the duration of the second time threshold can be represented by the number of symbols. For example, when the subcarrier spacing is 15kHz, the second time threshold is greater than or equal to 14 symbols; when the subcarrier spacing is 30kHz, the second time threshold is greater than or equal to 28 symbols. Optionally, when the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal is greater than the second time threshold (or the time interval between the reception time of the first uplink reference signal and the transmission time of the downlink reference signal is greater than the second time threshold), the transmission phase difference measured by the access network device may not be related to the reception phase difference determined based on the downlink reference signal, and therefore cannot be used for uplink and downlink reciprocity correction on the terminal side.

[0125] In one possible implementation (3), the time interval between the transmission time of the first uplink reference signal and the reception time of the first indication information is less than or equal to a third time threshold (e.g., Δt3). That is, for the terminal, the time interval between the moment the terminal transmits the first uplink reference signal and the moment the terminal receives the first indication information transmitted by the access network device does not exceed the third time threshold. Optionally, it can also be said that the time interval between the reception time of the first uplink reference signal and the transmission time of the first indication information is less than or equal to the third time threshold. That is, for the access network device, the time interval between the moment the access network device receives the first uplink reference signal transmitted by the terminal and the moment the access network device transmits the first indication information is less than or equal to the third time threshold. Optionally, when the time interval between the transmission time of the first uplink reference signal and the reception time of the first indication information is greater than the third time threshold (or the time interval between the reception time of the first uplink reference signal and the transmission time of the first indication information is greater than the third time threshold), the transmission phase difference measured by the access network device may not be related to the reception phase difference determined based on the downlink reference signal, and therefore cannot be used for uplink-downlink reciprocity correction on the terminal side.

[0126] Understandably, as described above, the terminal's transmit phase difference includes the transmit antenna port phase difference δT caused by the terminal's hardware factors and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. Similarly, the terminal's receive phase difference also includes the receive antenna port phase difference δR caused by the terminal's hardware factors and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. To eliminate the influence of δH, in this embodiment, the access network device can use the same antenna port as the one used to receive the first uplink reference signal to transmit the downlink reference signal, thereby ensuring the relative relationship of δH between antenna ports. That is, for the access network device, the antenna port used by the access network device to transmit the downlink reference signal (e.g., CSI-RS) is the same as the antenna port used by the access network device to receive the first uplink reference signal (e.g., AS SRS). Correspondingly, for the terminal, the antenna port used by the terminal to receive the downlink reference signal is the same as the antenna port used by the terminal to transmit the first uplink reference signal. This can eliminate the influence of δH on the transmit phase difference or receive phase difference.

[0127] It should be noted that the N-1 transmit phase differences and N-1 receive phase differences obtained in this embodiment are used for transmit phase compensation of the terminal's antenna ports. Specifically, after receiving the first indication information, the terminal can transmit a second uplink reference signal to the access network device through the aforementioned N antenna ports. Correspondingly, the access network device can receive the second uplink reference signal from the terminal through these N antenna ports. The transmit antenna ports of the second uplink reference signal have undergone phase compensation, or in other words, the terminal performs transmit phase compensation on its antenna ports when transmitting the second uplink reference signal. For example, the second uplink reference signal can be a beamforming (BF) SRS, abbreviated as BF SRS, or the second uplink reference signal can also be a non-codebook (NCB) based SRS, abbreviated as NCB SRS. For example, the N-1 phase difference compensation values ​​between the N-1 antenna ports of the aforementioned terminal and the reference antenna port can be determined based on the aforementioned N-1 transmit phase differences and the aforementioned N-1 receive phase differences. For instance, assuming the terminal contains two antenna ports (i.e., N=2) and these two antenna ports are antenna port 1 and antenna port 2, and assuming the reference antenna port is antenna port 1, where the transmit phase difference between antenna port 2 and antenna port 1 is transmit phase difference 21, and the receive phase difference between antenna port 2 and antenna port 1 is receive phase difference 21, then the phase difference compensation value between antenna port 2 and antenna port 1 can be equal to transmit phase difference 21 minus receive phase difference 21, or, the phase difference compensation value between antenna port 2 and antenna port 1 can be equal to receive phase difference 21 minus transmit phase difference 21. Optionally, the phase difference compensation value can also be simply referred to as the compensation value.

[0128] The so-called transmit phase compensation of the terminal's antenna ports can be categorized in two ways. One is that the transmit phase difference between the aforementioned N-1 antenna ports and the reference antenna port after command compensation (or the transmit phase difference between the aforementioned N-1 antenna ports used to transmit the second uplink reference signal and the reference antenna port) is equal to the N-1 receive phase differences between the N-1 antenna ports and the reference antenna port measured based on the downlink reference signal. For ease of description, this is referred to as compensation method ① below. The other is that the transmit phase difference between the N-1 antenna ports and the reference antenna port after command compensation (or the transmit phase difference between the N-1 antenna ports used to transmit the second uplink reference signal and the reference antenna port) is equal to the N-1 transmit phase differences between the N-1 antenna ports and the reference antenna port measured based on the first uplink reference signal. For ease of description, this is referred to as compensation method ② below.

[0129] For example, suppose a terminal has three antenna ports (N=3), namely antenna port 1, antenna port 2, and antenna port 3. Assume that the reference antenna port is antenna port 1, and the transmission phase difference between antenna port 2 and antenna port 1 is a transmission phase difference 21 (this transmission phase difference 21 = δT). 21 +δH 21 The transmission phase difference between antenna port 3 and antenna port 1 is the transmission phase difference 31 (this transmission phase difference 31 = δT). 31 +δH 31 The receiving phase difference between antenna port 2 and antenna port 1 is the receiving phase difference 21' (which is δR). 21 +δH 21 The receiving phase difference between antenna port 3 and antenna port 1 is called the receiving phase difference 31' (which is equal to δR). 31 +δH 31 If compensation method ① is used, then the compensation value for the transmit phase difference between antenna port 2 and antenna port 1 is δR. 21 -δT 21 The compensation value for the transmit phase difference between antenna port 3 and antenna port 1 is δR. 31 -δT 31 If compensation method ② is used, the compensation value for the phase difference between antenna port 2 and antenna port 1 is δT. 21 -δR 21 The compensation value for the transmit phase difference between antenna port 3 and antenna port 1 is δT. 31 -δR 31.

[0130] To make the scheme described in the embodiments of this application clearer, please refer to Figure 6. Figure 6 is a schematic diagram of the application scenario of uplink and downlink reciprocity correction of the terminal provided in the embodiments of this application. As shown in Figure 6, taking a terminal including antenna port 1 and antenna port 2 as an example, the terminal sends AS SRS to the base station through antenna port 1 and antenna port 2. Correspondingly, the base station can obtain the transmission phase difference Δθ of the terminal by measuring the AS SRS sent by the terminal. TX The transmitted phase difference Δθ TX The transmission phase difference Δθ is the phase difference between antenna port 1 and antenna port 2 of the terminal. TX This includes the phase difference δT between the transmitting antenna ports of the terminal due to hardware factors and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. The base station sends a first indication information to the terminal, which indicates the aforementioned transmission phase difference Δθ. TX Simultaneously, before, or after the base station sends the first indication information to the terminal, it also sends a CSI-RS to the terminal. Correspondingly, the terminal can obtain the received phase difference Δθ by measuring the CSI-RS sent by the base station. TX The received phase difference Δθ RX The receiving phase difference Δθ is the phase difference between antenna port 1 and antenna port 2 of the terminal. RX This includes the phase difference δR between the receiving and receiving antenna ports of the terminal due to hardware factors, and the phase difference δH caused by the different channels experienced by different antenna ports of the terminal. To eliminate the effect of δH, the base station uses the same antenna port as the one used to receive AS SRS to transmit CSI-RS (or, in other words, the terminal uses the same antenna port as the one used to transmit AS SRS to receive CSI-RS), thus ensuring the relative relationship of δH between the antenna ports. The terminal can complete reciprocity calibration by performing phase difference compensation δR-δT or δT-δR.

[0131] It should be noted that when the compensation value is δR - δT, and the terminal uses antenna port 1 and antenna port 2 to transmit BF SRS or NCB SRS, the transmission phase difference between antenna port 1 and antenna port 2 can be understood as equal to δR + δH (or as the transmission phase difference between antenna port 1 and antenna port 2 is δR). When the compensation value is δT - δR, and the terminal uses antenna port 1 and antenna port 2 to transmit BF SRS or NCB SRS, the transmission phase difference between antenna port 1 and antenna port 2 can be understood as equal to δT + δH (or as the transmission phase difference between antenna port 1 and antenna port 2 is δT). In other words, performing phase compensation before transmitting the second uplink reference signal ensures that the terminal's transmission phase difference equals the terminal's reception phase difference (or, as understood, that the terminal's transmission phase difference equals the terminal's reception phase difference). This improves the matching between precoding and actual uplink channel information when using downlink channel information as uplink channel information for precoding transmission, thereby improving precoding accuracy and transmission performance.

[0132] In this embodiment of the application, reciprocity calibration is performed by the base station-assisted terminal (i.e., the base station sends a first indication information to the terminal), and the time interval between the time when the base station sends the first indication information to the terminal and the time when the base station sends a reference signal for the terminal to measure the received phase difference is limited to no more than a first time threshold, which can realize channel reciprocity correction between the antenna ports of the terminal.

[0133] Optionally, the embodiments shown in Figure 5 above can also be applied to O-RAN scenarios. It should be understood that in O-RAN scenarios, the access network device involved in Figure 5 can be replaced by CU (e.g., CU-CP or CU-UP) or DU or RU, etc.

[0134] The communication device provided in this application will now be described in detail with reference to Figures 7 to 9.

[0135] It is understood that, in order to achieve the functions in the above embodiments, the communication device includes hardware structures and / or software modules corresponding to each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0136] Figures 7 to 9 are schematic diagrams illustrating the possible communication devices provided in the embodiments of this application. These communication devices can be used to implement the functions of the terminal or access network device (e.g., base station) in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be one of the terminals 120a-120j shown in Figure 1, or it can be RAN node 110a or 110b shown in Figure 1. Optionally, it can also be a module (e.g., a chip) applied to the terminal or access network device.

[0137] As shown in Figure 7, the communication device 700 includes a processing unit 710 and a transceiver unit 720. The transceiver unit 720 and the processing unit 710 can be software, hardware, or a combination of both. Optionally, the communication device 700 may further include a storage unit 730 for storing device program code and / or data, not shown in Figure 7.

[0138] The transceiver unit 720 can implement sending and / or receiving functions. Optionally, the transceiver unit 720 can also be referred to as a communication unit. The transceiver unit 720 may further include a receiving unit and / or a sending unit, wherein the receiving unit is used to implement the receiving function, and the sending unit is used to implement the sending function. Optionally, the transceiver unit 720 can be used to receive information sent by other devices, and can also be used to send information to other devices.

[0139] The communication device 700 is used to implement the functions of the terminal-side communication device in the method embodiment shown in FIG5 above. For example, the terminal-side communication device may be a terminal or a communication module in the terminal, or a circuit or chip in the terminal responsible for communication functions. Alternatively, the communication device 700 is used to implement the functions of the network-side communication device in the method embodiment shown in FIG5 above. For example, the network-side communication device may be an access network device, a module (e.g., a circuit, chip, or chip system) in the access network device, or a logic node, logic module, or software that can implement all or part of the functions of the access network device.

[0140] When the communication device 700 is used to implement the functions of the terminal in the method embodiment shown in FIG5:

[0141] The transceiver unit 720 is configured to receive first indication information, which indicates N-1 transmission phase differences between the N-1 antenna ports of the terminal and a reference antenna port, respectively. The terminal includes N antenna ports, which include the N-1 antenna ports and the reference antenna port, where N is an integer greater than 1. The transceiver unit 720 is also configured to receive a downlink reference signal, which is used to determine N-1 reception phase differences between the N-1 antenna ports and the reference antenna port, wherein the time interval between the reception time of the first indication information and the reception time of the downlink reference signal is less than or equal to a first time threshold, and the N-1 transmission phase differences and the N-1 reception phase differences are used for transmission phase compensation of the terminal's antenna ports. Optionally, the processing unit 710 is configured to process the received downlink reference signal.

[0142] In one possible implementation, before receiving the first indication information, the transceiver unit 720 is further configured to:

[0143] A first uplink reference signal is transmitted, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, respectively.

[0144] In one possible implementation, when the first downlink reference signal is transmitted aperiodically, the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal is less than or equal to a second time threshold.

[0145] In one possible implementation, the second time threshold is greater than or equal to 1 ms.

[0146] In one possible implementation, the N antenna ports used to receive the downlink reference signal are the same as the N antenna ports used to transmit the first uplink reference signal.

[0147] In one possible implementation, the first indication information is carried in a first message, which includes any of the following: an RRC message, a MAC CE, or a DCI.

[0148] In one possible implementation, the N-1 transmission phase differences include a first transmission phase difference, which is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports; the first transmission phase difference is carried by multiple bits in the first message.

[0149] In one possible implementation, after receiving the first indication information, the transceiver unit 720 is further configured to:

[0150] A second uplink reference signal is transmitted, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

[0151] In one possible implementation, after receiving the first indication information, the method further includes:

[0152] Based on the N-1 transmit phase differences and the N-1 receive phase differences, determine the N-1 phase difference compensation values ​​between the N-1 antenna ports and the reference antenna port respectively;

[0153] The second uplink reference signal is sent based on the N-1 phase difference compensation values.

[0154] In one possible implementation, the first time threshold is 1ms or 2ms.

[0155] In one possible design, when the communication device 700 is a terminal or a communication module within a terminal, the functionality of the processing unit 710 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) or SIP chip containing a modem core. The functionality of the transceiver unit 720 can be implemented by transceiver circuitry.

[0156] In one possible design, when the communication device 700 is a circuit or chip in a terminal responsible for communication functions, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing unit 710 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the transceiver unit 720 can be implemented by the interface circuitry or data transceiver circuitry on the aforementioned chip.

[0157] When the communication device 700 is used to implement the function of the access network device in the method embodiment shown in FIG5:

[0158] The transceiver unit 720 is configured to transmit first indication information, which indicates N-1 transmission phase differences between the N-1 antenna ports of the terminal and a reference antenna port, respectively. The terminal includes N antenna ports, which include the N-1 antenna ports and the reference antenna port, where N is an integer greater than 1. The transceiver unit 720 is configured to transmit a downlink reference signal, which is used to determine N-1 reception phase differences between the N-1 antenna ports and the reference antenna port, wherein the time interval between the transmission time of the first indication information and the transmission time of the downlink reference signal is less than or equal to a first time threshold, and the N-1 transmission phase differences and the N-1 reception phase differences are used for transmission phase compensation of the antenna ports of the terminal.

[0159] In one possible implementation, before sending the first indication information, the transceiver unit 720 is further configured to:

[0160] A first uplink reference signal is received, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port. Optionally, the processing unit 710 is used to process the received first uplink reference signal.

[0161] In one possible implementation, when the first downlink reference signal is transmitted aperiodically, the time interval between the reception time of the first uplink reference signal and the transmission time of the downlink reference signal is less than or equal to a second time threshold.

[0162] In one possible implementation, the second time threshold is greater than or equal to 1 ms.

[0163] In one possible implementation, the N antenna ports of the access network device used to transmit the downlink reference signal are the same as the N antenna ports of the access network device used to receive the first uplink reference signal.

[0164] In one possible implementation, the first indication information is carried in a first message, which includes any of the following: an RRC message, a MAC CE, or a DCI.

[0165] In one possible implementation, the N-1 transmission phase differences include a first transmission phase difference, which is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports; the first transmission phase difference is carried by multiple bits in the first message.

[0166] In one possible implementation, after sending the first indication information, the transceiver unit 720 is further configured to:

[0167] Receive a second uplink reference signal, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

[0168] In one possible implementation, the first time threshold is 1ms or 2ms.

[0169] For a more detailed description of the processing unit 710 and the transceiver unit 720, please refer to the relevant description in the method embodiment shown in FIG5.

[0170] It is understood that the division of units in the above-described device is merely a logical functional division. Each function can correspond to a functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into a single physical entity, or they can be distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed 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.

[0171] In one example, the functional unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0172] In one example, storage unit 730 may include random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory and / or registers, etc.

[0173] As shown in Figure 8, the communication device 800 includes a processor 810, and optionally, an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It is understood that the interface circuit 820 can be a transceiver or an input / output interface. Optionally, the communication device 800 may also include a memory 830 for storing computer programs or instructions executed by the processor 810, or storing input data required by the processor 810 to execute instructions, or storing data generated by the processor 810 after executing computer programs or instructions.

[0174] When the communication device 800 is used to implement the method shown in FIG5, the processor 810 is used to implement the function of the processing unit 710, and the interface circuit 820 is used to implement the function of the transceiver unit 720.

[0175] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiments. The terminal chip receives information sent to the terminal by the access network device through other modules (such as an RF module or antenna) in the terminal; or, the terminal chip sends information to other modules (such as an RF module or antenna) in the terminal, which is information sent by the terminal to the access network device.

[0176] When the aforementioned communication device is a module applied to an access network device, the access network device module implements the functions of the access network device in the above method embodiments. The access network device module receives information from other modules (such as radio frequency modules or antennas) in the access network device, which is information sent by the terminal to the access network device; or, the access network device module sends information to other modules (such as radio frequency modules or antennas) in the access network device, which is information sent by the access network device to the terminal. Here, the access network device module can be the baseband chip of the access network device, or a CU, DU, or other module, or a device under an open radio access network (O-RAN) architecture, such as an open CU, open DU, etc.

[0177] As shown in Figure 9, the communication device 900 includes a processor 910, a memory 920, and a transceiver 930. The processor 910 is mainly used for processing communication protocols and communication data; controlling terminal / access network devices; executing software programs; and processing data from software programs. The memory 920 can store computer program code, software programs, and data. The transceiver 930 includes a transmitter 931, a receiver 932, radio frequency circuitry (not shown in the figure), and an antenna 933.

[0178] The processor 910 can also be called a processing unit, processing board, processing module, or processing device. The transceiver 930 can also be called a transceiver unit, transceiver, or transceiver device.

[0179] Optionally, the devices in transceiver 930 used to implement the receiving function can be considered as receiving modules, and the devices in transceiver 930 used to implement the transmitting function can be considered as transmitting modules. That is, transceiver 930 includes a receiver and / or a transmitter. A transceiver may also be called a transceiver unit, transceiver module, or transceiver circuit, etc. A receiver may also be called a receiver unit, receiving module, or receiving circuit, etc. A transmitter may also be called a transmitter, transmitting module, or transmitting circuit, etc.

[0180] Processor 910 is used to execute terminal-side processing operations in the embodiment shown in FIG. 5. Transceiver 930 is used to execute terminal-side transmission and reception operations in the embodiment shown in FIG. 5. Alternatively, processor 910 is used to execute network-side processing operations in the embodiment shown in FIG. 5. Transceiver 930 is used to execute network-side transmission and reception operations in the embodiment shown in FIG. 5.

[0181] When the communication device is a chip, the chip includes a processor and a transceiver. The transceiver can be an input / output circuit or a communication interface. The processor can be a processing module integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the terminal's transmitting operation can be understood as the chip's output, and the terminal's receiving operation can be understood as the chip's input. Similarly, in the above method embodiments, the access network device's transmitting operation can be understood as the chip's output, and the access network device's receiving operation can be understood as the chip's input.

[0182] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the methods executed by a terminal or access network device in the above-described method embodiments.

[0183] For example, when the computer program or instructions are executed by the computer, the computer can implement the method performed by the terminal or access network device in the above method embodiments.

[0184] This application also provides a computer program product containing a program or instructions, which, when executed by a computer, causes the computer to implement the method executed by the terminal or access network device in the above method embodiments.

[0185] This application also provides a communication system, which includes the terminal and the access network device described in the above embodiments. The terminal is used to perform some or all of the operations performed by the terminal in the above method embodiments, and the access network device is used to perform some or all of the operations performed by the access network device in the above method embodiments.

[0186] This application also provides a chip device, including a processor, for calling a computer program or computer instructions stored in the memory, so that the processor executes the method provided in the embodiment shown in FIG5 above.

[0187] In one possible implementation, the input of the chip device corresponds to the receiving operation in any of the embodiments shown in FIG5 above, and the output of the chip device corresponds to the sending operation in any of the embodiments shown in FIG5 above.

[0188] Optionally, the processor is coupled to the memory via an interface.

[0189] Optionally, the chip device further includes a memory storing computer programs or computer instructions.

[0190] It is understood that the processor in the embodiments of this application can be a CPU, or other general-purpose processors, DSPs, ASICs, FPGAs, 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.

[0191] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in an access network device or terminal. The processor and storage medium can also exist as discrete components in the access network device or terminal.

[0192] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0193] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0194] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, include: The terminal receives a first indication message, which indicates N-1 transmission phase differences between the terminal's N-1 antenna ports and a reference antenna port. The terminal includes N antenna ports, which include the N-1 antenna ports and the reference antenna port, where N is an integer greater than 1. A downlink reference signal is received, which is used to determine N-1 receive phase differences between the N-1 antenna ports and the reference antenna port, respectively. The time interval between the reception time of the first indication information and the reception time of the downlink reference signal is less than or equal to a first time threshold. The N-1 transmit phase differences and the N-1 receive phase differences are used for transmit phase compensation of the antenna ports of the terminal.

2. The method according to claim 1, characterized in that, Before receiving the first indication information, the method further includes: A first uplink reference signal is transmitted, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, respectively.

3. The method according to claim 2, characterized in that, When the first downlink reference signal is transmitted aperiodically, the time interval between the transmission time of the first uplink reference signal and the reception time of the downlink reference signal is less than or equal to the second time threshold.

4. The method according to claim 2 or 3, characterized in that, The N antenna ports used to receive the downlink reference signal are the same as the N antenna ports used to transmit the first uplink reference signal.

5. The method according to any one of claims 1-4, characterized in that, After receiving the first indication information, the method further includes: A second uplink reference signal is transmitted, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

6. The method according to any one of claims 1-4, characterized in that, After receiving the first indication information, the method further includes: Based on the N-1 transmit phase differences and the N-1 receive phase differences, determine the N-1 phase difference compensation values ​​between the N-1 antenna ports and the reference antenna port respectively; The second uplink reference signal is sent based on the N-1 phase difference compensation values.

7. A communication method, characterized in that, include: Send a first indication message, the first indication message indicating the N-1 transmission phase differences between the N-1 antenna ports of the terminal and the reference antenna port respectively, the terminal including N antenna ports, the N antenna ports including the N-1 antenna ports and the reference antenna port, the N being an integer greater than 1; A downlink reference signal is transmitted, which is used to determine N-1 receive phase differences between the N-1 antenna ports and the reference antenna port, respectively. The time interval between the transmission time of the first indication information and the transmission time of the downlink reference signal is less than or equal to a first time threshold. The N-1 transmit phase differences and the N-1 receive phase differences are used for transmit phase compensation of the antenna ports of the terminal.

8. The method according to claim 7, characterized in that, Before sending the first indication information, the method further includes: A first uplink reference signal is received, which is used to determine the N-1 transmission phase differences between the N-1 antenna ports and the reference antenna port, respectively.

9. The method according to claim 8, characterized in that, When the first downlink reference signal is transmitted aperiodically, the time interval between the reception time of the first uplink reference signal and the transmission time of the downlink reference signal is less than or equal to the second time threshold.

10. The method according to claim 8 or 9, characterized in that, The N antenna ports of the access network device used to transmit the downlink reference signal are the same as the N antenna ports of the access network device used to receive the first uplink reference signal.

11. The method according to any one of claims 7-10, characterized in that, After sending the first indication information, the method further includes: Receive a second uplink reference signal, which is a non-codebook-based detection reference signal or a beamformed detection reference signal.

12. The method according to claim 3 or 9, characterized in that, The second time threshold is greater than or equal to 1ms.

13. The method according to any one of claims 1-11, characterized in that, The first indication information is carried in a first message, which includes any one of the following: a Radio Resource Control (RRC) message, a Media Access Control (MAC) CE message, or a Downlink Control Information (DCI) message.

14. The method according to claim 13, characterized in that, The N-1 transmission phase differences include a first transmission phase difference, which is the transmission phase difference between the first antenna port and the reference antenna port, and the first antenna port is one of the N-1 antenna ports; the first transmission phase difference is carried by multiple bits in the first message.

15. The method according to any one of claims 1-14, characterized in that, The first time threshold is 1ms or 2ms.

16. A communication device, characterized in that, It includes units or modules for implementing the method as described in any one of claims 1-6, 12-15, or includes units or modules for implementing the method as described in any one of claims 7-15.

17. A communication device, characterized in that, Includes a processor for executing computer programs or instructions to cause the communication device to implement the method as described in any one of claims 1-6, 12-15, or to cause the communication device to implement the method as described in any one of claims 7-15.

18. A communication device, characterized in that, The device includes a processor and a transceiver, the transceiver being used to send and receive information, and the processor being used to execute computer programs or instructions to cause the communication device to implement the method as described in any one of claims 1-6, 12-15, or to cause the communication device to implement the method as described in any one of claims 7-15.

19. A communication device, characterized in that, The device includes a processor and an interface circuit. The interface circuit is used to receive signals from other communication devices besides the communication device and transmit them to the processor, or to send signals from the processor to other communication devices besides the communication device. The processor is used to execute computer programs or instructions to cause the communication device to implement the method as described in any one of claims 1-6, 12-15, or to cause the communication device to implement the method as described in any one of claims 7-15.

20. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1-6 and 12-15, or implement the method as described in any one of claims 7-15.

21. A computer program product, characterized in that, Includes computer program code, which, when run on a computer, implements the method of any one of claims 1-6, 12-15, or implements the method of any one of claims 7-15.

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