Communication method and device

Abstract

This application provides a communication method and device applicable to the communication field. The method includes: receiving, by an access network device, first information, where the first information indicates a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in a terminal device; decoding, via the second decoder, a coded bitstream corresponding to channel data to obtain channel information; determining a first value of a rank based on the first performance difference and the channel information; and sending the first value and a channel quality indicator corresponding to the first value to the access network device. According to the method provided in this application, the terminal device determines the first value of the rank based on the first performance difference fed back by the access network device. As a result, the first value fed back by the terminal device to the access network device better matches the precoding matrix determined by the access network device, improving the accuracy and precision of the feedback.

Description

Technical Field

[0001] [Related Application] This application claims priority to Chinese Patent Application No. 202210617141.2, filed with the China National Intellectual Property Administration on June 1, 2022, and entitled "COMMUNICATION METHOD AND APPARATUS", which is hereby incorporated by reference in its entirety. [Technical Field] This application relates to the field of communication technologies, and in particular, to communication methods and devices.

Background Art

[0002] The wireless communication system formulated by the 3rd generation partnership project (3GPP) evolved into the 5th generation (5G) system, i.e., the new radio (NR) system. The 5G communication system has higher requirements for system capacity, spectral efficiency, etc. In the 5G communication system, in order to improve the spectral efficiency of the system, the application of massive multiple-input multiple-output (massive MIMO) technology plays an important role. By using massive MIMO technology, the base station can provide high-quality services to more user equipment (UE) simultaneously. The key step is that the base station precodes the downlink data. Through precoding, spatial multiplexing can be implemented, the interference between different data streams can be reduced, the signal to interference plus noise ratio (SINR) at the receiving end can be increased, and the system throughput can be increased. In order for the base station to more accurately precode the downlink data of the UE, the UE feeds back the channel state information (CSI) of the downlink channel to the base station, the base station restores the downlink channel information based on the CSI, determines the precoding matrix using the restored downlink channel information, and performs precoding. How to enable the base station to obtain more accurate channel state information is a technical problem worthy of research.

Summary of the Invention

[0003] This application provides a communication method and device for enabling the network side to obtain more accurate channel state information.

[0004] According to the first aspect, a first communication method is provided. The method may be executed on the terminal device side. The method may be executed by software, hardware, or a combination of hardware and software. For example, the method may be executed by a terminal device, or by a circuit system, or by a large device including the terminal device. The circuit system can implement the functions of the terminal device. The method includes the following. The terminal device receives first information from an access network device, where the first information is used to determine a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in the terminal device, decodes a coded bitstream corresponding to channel data via the second decoder to obtain channel information, determines a first value of the rank based on the first performance difference and the channel information, sends a rank indicator indicating the first value and a channel quality indicator corresponding to the first value to the access network device.

[0005] According to the foregoing method, the terminal device determines a first value of the rank based on the first performance difference fed back by the access network device. As a result, the first value fed back by the terminal device to the access network device better matches the precoding matrix determined by the access network device, improving the accuracy and correctness of the feedback.

[0006] In a possible implementation, the method further includes the step of sending, to the access network device, a coded bitstream corresponding to the channel data.

[0007] In a possible implementation, the first information and the first performance difference satisfy a relationship of a preset function, The method further includes the step of using, as the first performance difference, an output value of a preset function obtained by using the first information as an input value.

[0008] In this implementation, since the first information and the first performance difference satisfy the relationship of a preset function, the flexibility of the feedback of the first performance difference can be improved, thereby improving the system efficiency.

[0009] In a possible implementation, the first information is an index of the first performance difference, The method further includes the step of using the performance difference with the first information as an index as the first performance difference.

[0010] In this implementation, the first information is an index of the first performance difference. This implementation is flexible and can reduce the overhead for transmitting the first information.

[0011] In a possible embodiment, the first information is an index of the second performance difference, and the second performance difference is the performance difference between the performance of the first decoder and a pre-configured reference performance. The method further includes the step of determining the first performance difference based on the second performance difference and the reference performance.

[0012] In a possible implementation, the first information is the first performance difference.

[0013] In this implementation, the terminal device can directly determine the first performance difference based on the first information. This implementation has low complexity and can reduce the complexity of the system.

[0014] In a possible implementation, the maximum value of the rank is N, the first information indicates N first performance differences, and N is an integer greater than 0. Each of the N first performance differences corresponds to one stream.

[0015] In this implementation, each stream of the channel corresponds to one first performance difference, so the feedback accuracy can be improved.

[0016] In a possible implementation, the step of determining the first value of the rank based on the first performance difference and the channel information is A step of determining a channel indicator corresponding to each of N values of a rank based on a first performance difference and channel information, where N is an integer greater than 0, the step; A step of using, as a first value, a value of an optimal channel indicator among the channel indicators corresponding to the N values; including.

[0017] In this implementation, since the value of the optimal channel indicator is used as the first value, the channel throughput can be improved, thereby improving the system efficiency.

[0018] According to a second aspect, a first communication method is provided. The method may be executed on the access network device side. The method may be executed by software, hardware, or a combination of hardware and software. For example, the method may be executed by an access network device, or by a circuit system, or by a large device including the access network device. The circuit system can implement the functions of the access network device. The method includes the following. The access network device determines a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in the terminal device, transmits first information to the terminal device, and the first information is used to determine the first performance difference, receives from the terminal device a rank indicator and a channel quality indicator corresponding to the first value, the rank indicator indicates the first value, the first value is determined based on the first performance difference and channel information, and the channel information is obtained by decoding a coded bitstream corresponding to channel data via the second decoder.

[0019] In a possible implementation, the method further includes a step of transmitting, by the access network device, a coded bitstream corresponding to the channel data.

[0020] In a possible implementation, the first information and the first performance difference satisfy the relationship of a preset function. When the input value of the preset function is the first information, the output value of the preset function is the first performance difference.

[0021] In a possible implementation, the first information is an indicator of the first performance difference.

[0022] In a possible implementation, the first information is an indicator of the second performance difference. The second performance difference is the performance difference between the performance of the first decoder and a preset reference performance. The first performance difference is determined based on the second performance difference and the reference performance.

[0023] In a possible implementation, the maximum value of the rank is N, the first information indicates N first performance differences, and N is an integer greater than 0.

[0024] In a possible implementation, the first value is the value of the optimal channel indicator in the channel indicators corresponding to N values of the rank. N is an integer greater than 0, and each of the channel indicators corresponding to the N values of the rank is determined based on the first performance difference and the channel information.

[0025] According to a third aspect, embodiments of the present application provide a communication device. The communication device may be a terminal device, a module capable of implementing functions on the terminal device side, or a chip that can be disposed within the terminal device. The communication device has functions for implementing the first aspect. For example, the communication device includes corresponding modules, units, or means for executing some or all of the steps in the first aspect. The functions, units, or means may be implemented using software or hardware, or may be implemented by hardware that executes the corresponding software.

[0026] In a possible design, the communication device includes a processing unit and a communication unit. The communication unit may be configured to transmit and receive signals and implement communication between the communication device and other devices. For example, the communication unit may be configured to receive information from a second device, and the processing unit may be configured to execute some internal operations of the communication device. The functions performed by the processing unit and the communication unit may correspond to the operations of the first aspect.

[0027] In a possible design, the communication device includes a processor and may further include a transceiver. The transceiver is configured to transmit and receive signals, and the processor is configured to achieve a method according to any one of the possible designs or implementations of the first aspect by using the transceiver. The communication device may further include one or more memories. The memory is coupled to the processor, and the memory can store a computer program or instructions for implementing the functions in the first aspect. The processor can execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device can implement a method according to any one of the possible designs or implementations of the first aspect.

[0028] In a possible design, the communication device includes a processor, and the processor may be coupled to a memory. The memory can store a computer program or instructions for implementing the functions in the first aspect. The processor can execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device can implement a method according to any one of the possible designs or implementations of the first aspect.

[0029] In a possible design, the communication device includes a processor and an interface circuit. The processor is configured to communicate with another device through the interface circuit and execute a method according to any one of the possible designs or implementations of the first aspect.

[0030] According to a fourth aspect, embodiments of the present application provide a communication device. The communication device may be an access network device, a module capable of performing functions on the access network device side, or a chip that can be disposed within the access network device. The communication device has functions for implementing the second aspect. For example, the communication device includes corresponding modules, units, or means for performing operations in the second aspect. The modules, units, or means may be implemented using software or hardware, or may be implemented by hardware that executes corresponding software.

[0031] In a possible design, the communication device includes a processing unit and a communication unit. The communication unit may be configured to transmit and receive signals and implement communication between the communication device and other devices. For example, the communication unit may be configured to receive information from a first device, and the processing unit may be configured to execute some internal operations of the communication device. The functions executed by the processing unit and the communication unit may correspond to the operations of the second aspect.

[0032] In a possible design, the communication device includes a processor and may further include a transceiver. The transceiver is configured to transmit and receive signals, and the processor uses the transceiver to achieve a method according to any one of the possible designs or implementations of the second aspect. The communication device may further include one or more memories. The memory is coupled to the processor, and the memory can store a computer program or instructions for implementing functions in the second aspect. The processor can execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device can implement a method according to any one of the possible designs or implementations of the second aspect.

[0033] In a possible design, the communication device includes a processor, and the processor may be coupled to a memory. The memory can store a computer program or instructions for implementing the functions in the second aspect. The processor can execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device can implement a method according to any one of the possible designs or implementations of the second aspect.

[0034] In a possible design, the communication device includes a processor and an interface circuit. The processor is configured to communicate with another device through the interface circuit and execute a method according to any one of the possible designs or implementations of the second aspect.

[0035] According to a fifth aspect, an embodiment of the present application provides a communication system. The communication system includes a communication device according to the third aspect and a communication device according to the fourth aspect.

[0036] According to a sixth aspect, a chip is provided. The chip includes a processor, further includes a memory, and is configured to execute a computer program or instructions stored in the memory, enabling the chip to implement a method according to any one of the first aspect and possible implementations of the first aspect, or enabling the chip to implement a method according to any one of the second aspect and possible implementations of the second aspect.

[0037] According to a seventh aspect, an embodiment of the present application provides a computer-readable storage medium. The computer storage medium stores computer-readable instructions. When a computer reads and executes the computer machine-readable instructions, the computer is enabled to implement the method described in any one of the possible designs of the first aspect and the second aspect.

[0038] According to an eighth aspect, an embodiment of the present application provides a computer program product. When a computer reads and executes the computer program product, the computer is enabled to implement the method described in any one of the possible designs of the first aspect and the second aspect.

[0039] According to the ninth aspect, an embodiment of the present application provides a chip. The chip includes a processor. The processor is coupled to a memory and is configured to read and execute a software program stored in the memory to implement a method according to any one of the possible implementations of the first aspect and the second aspect.

[0040] According to the tenth aspect, a communication device including a processor and an interface circuit is provided. The interface circuit is configured to receive a signal from another communication device other than the communication device and transmit the signal to the processor, or transmit a signal from the processor to another communication device other than the communication device. The processor is configured to implement a method according to any one of the first aspect and the possible implementations of the first aspect by using a logic circuit or by executing a computer program or instruction.

[0041] According to the eleventh aspect, a communication device including a processor and an interface circuit is provided. The interface circuit is configured to receive a signal from another communication device other than the communication device and transmit the signal to the processor, or transmit a signal from the processor to another communication device other than the communication device. The processor is configured to implement a method according to any one of the second aspect and the possible implementations of the second aspect or a method according to any one of the third aspect and the possible implementations of the third aspect by using a logic circuit or by executing a computer program or instruction.

[0042] According to the twelfth aspect, a communication device including a processor and a memory is provided. The processor is coupled to the memory and is configured to execute a computer program or instruction stored in the memory, enabling the communication device to implement a method according to any one of the first aspect and the possible implementations of the first aspect.

[0043] According to the 13th aspect, a communication device including a processor and a memory is provided. The processor is coupled to the memory, and the processor is configured to execute a computer program or instructions stored in the memory, enabling the communication device to implement the method according to any one of the 2nd aspect and possible implementations of the 2nd aspect.

[0044] These aspects or other aspects of the present application will be more clearly understood in the following description of the embodiments.

Brief Description of the Drawings

[0045]

Figure 1

[0046]

Figure 2

[0047]

Figure 3

[0048]

Figure 4

[0049]

Figure 5

[0050]

Figure 6

Modes for Carrying Out the Invention

[0051] To clarify the objectives, technical solutions, and advantages of the present application, the following will describe the present application in detail with reference to the accompanying drawings.

[0052] The technology provided in this application can be applied to the communication system 10 shown in FIG. 1. The communication system 10 includes one or more communication devices 30 (e.g., terminal devices). The one or more communication devices 30 are connected to one or more core network (CN) devices via one or more radio access network (RAN) devices 20 to realize communication between multiple communication devices. For example, the communication system 10 is a communication system that supports 4th generation (4G) (including long term evolution (LTE)) access technology, a communication system that supports 5G (sometimes also called new radio (NR)) access technology, a wireless fidelity (Wi-Fi) system, a cellular system related to the 3rd generation partnership project (3GPP), a communication system that supports the convergence of multiple wireless technologies, or a future-oriented evolution system. This is not limited.

[0053] It should be understood that the number of devices in the communication system shown in FIG. 1 is used merely as an example, and this application is not limited thereto. In actual applications, the communication system can further include more terminal devices and more access network devices, and can further include other devices. For example, it can include a core network device and / or a node configured to implement an artificial intelligence function.

[0054] The network architecture shown in FIG. 1 is applicable to communication systems using various radio access technologies (RATs), such as 4G communication systems, 5G (also known as new radio (NR)) communication systems, transitional systems between LTE communication systems and 5G communication systems, which are sometimes also called 4.5G communication systems, or future communication systems, such as 6G communication systems. The network architecture and service scenarios described in this application are intended to more clearly explain the technical solutions in this application and do not constitute a limitation to the technical solutions provided in this application. Those skilled in the art can understand that the technical solutions provided in this application are also applicable to similar technical problems with the evolution of the network architecture and the emergence of new service scenarios.

[0055] Hereinafter, the terminal device and the access network device in FIG. 1 will be individually described in detail.

[0056] In this application, the terminal device may be simply referred to as a terminal. The terminal device may be a device having a wireless transceiver function. The terminal device may be mobile or fixed. The terminal device may be deployed on the ground, including indoor devices, outdoor devices, handheld devices, or in-vehicle devices, may be deployed on the water surface (e.g., on a ship), or may be deployed in the air (e.g., on an aircraft, balloon, or satellite). The terminal device may include a mobile phone, a tablet computer (Pad), a computer having a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical, a wireless terminal device in smart grid, a wireless terminal device in transportation safety, a wireless terminal device in smart city, a wireless terminal device in smart home. As an alternative, the terminal device may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device or a computing device with a wireless communication function, an in-vehicle device, a wearable device, a terminal device in a future 5th generation (5G) network, a terminal device in a future evolved Public Land Mobile Network (PLMN), etc. The terminal device may sometimes also be referred to as user equipment (UE). Optionally, the terminal device can communicate with multiple access network devices using different technologies.For example, the terminal device can communicate with an access network device that supports LTE, can communicate with an access network device that supports 5G, and can also implement dual connectivity of an access network device that supports LTE and an access network device that supports 5G. This is not limited in the present application.

[0057] In the present application, the device configured to realize the functions of the terminal device may be the terminal device itself, or a device that can support the terminal device in realizing the functions, such as a chip system, a hardware circuit, a software module, or a combination of a hardware circuit and a software module. The device may be installed in the terminal device or used together with the terminal device. In the technical solution provided in the present application, an example in which the device configured to realize the functions of the terminal device is the terminal device and the terminal device is a UE is used to describe the technical solution provided in the present application.

[0058] In this application, an access network device is a node or device that connects a terminal device to a wireless network, and the access network device may also be referred to as a network device or a base station. The access network device includes, for example, but not limited to, a base station, a next-generation NodeB (gNB) in 5G, an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB or a home NodeB, HNB), a baseband unit (BBU), a transmission reception point (TRP), a transmission point (TP), and / or a mobile switching center. Alternatively, the access network device may be a module configured to perform some or all of the functions of a base station. For example, the access network device may be at least one of a central unit (CU), a distributed unit (DU), a central unit control plane (CU-CP) node, a central unit user plane (CU-UP) node, an integrated access and backhaul (IAB), or a radio controller in a cloud radio access network (CRAN) scenario. As an alternative, the access network device may be a relay station, an access point, a vehicle-mounted device, a terminal device, a wearable device, an access network device in a 5G network, an access network device in a future evolved public land mobile network (PLMN), etc.

[0059] In the present application, a device configured to implement the functions of an access network device may be an access network device, or a device capable of supporting the access network device in implementing functions, for example, a chip system, a hardware circuit, a software module, or a combination of a hardware circuit and a software module. The device may be installed in the access network device or used together with the access network device. In the technical solution provided in the present application, a device configured to implement the functions of an access network device is an access network device, and an example in which the access network device is a base station is used to describe the technical solution provided in the present application.

[0060] The communication between the access network device and the terminal device follows a specific protocol layer structure. The protocol layer structure can include a control plane protocol layer structure and a user plane protocol layer structure. For example, the structure of the control plane protocol layer may include at least one of the following: radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, Media Access Control (MAC) layer, and physical (PHY) layer. For example, the structure of the user plane protocol layer may include at least one of the following: service data adaptation protocol (SDAP) layer, PDCP layer, RLC layer, MAC layer, and physical layer.

[0061] The protocol layer structure between the access network device and the terminal device can be regarded as an access stratum (AS) structure. Optionally, a non-access stratum (NAS) can further exist on top of the AS and be used by the access network device to transfer information from the core network device to the terminal device or from the terminal device to the core network device. In this case, a logical interface can be considered to exist between the terminal device and the core network device. Optionally, the access network device can transfer information between the terminal device and the core network device through transparent transmission. For example, NAS messages can be mapped to or included in RRC signaling as elements of the RRC signaling.

[0062] Optionally, the protocol layer structure between the access network device and the terminal device may further include an AI layer used to transmit data related to artificial intelligence (AI) functions.

[0063] In addition to the communication between the access network device and the terminal device, the method provided in this application can be used for communication between other communication devices, for example, communication between a macro base station and a micro base station in a wireless backhaul link, or communication between a first terminal device and a second terminal device in a sidelink (SL). This is not limited. This application will be described by taking the communication between the access network device and the terminal device as an example.

[0064] When the access network device transmits data to the terminal device, it can perform precoding based on the channel state information (CSI) fed back from the terminal device. To facilitate the understanding of this application, the following briefly explains some technical terms in this application.

[0065] 1. Precoding Technology

[0066] When the channel state information is known, the access network device can process the transmission signal using a precoding matrix that matches the channel conditions. Based on this technology, since the precoded transmission signal can be matched to the channel, the quality of the signal received by the terminal device (e.g., signal to interference plus noise ratio (SINR)) is improved, and the system throughput is further improved. Based on the precoding technology, the transmitting device (e.g., the access network device) and multiple receiving devices (e.g., terminal devices) can effectively perform transmission on the same time-frequency resource. That is, multi-user multiple-input multiple-output (MU-MIMO) can be effectively realized. Based on the precoding technology, the transmitting device (e.g., the access network device) and the receiving device (e.g., the terminal device) can effectively transmit multiple data streams on the same time-frequency resource. That is, single-user multiple-input multiple-output (SU-MIMO) can be effectively realized. It should be noted that the related description of the precoding technology is merely an example for easy understanding and is not intended to limit the disclosure scope of this application. In a specific implementation process, the transmitting device may alternatively perform precoding in another way. For example, when channel information (e.g., not limited to the channel matrix) cannot be obtained, precoding is performed using a preset precoding matrix or by a weighting process. The specific content is omitted in this specification.

[0067] 2. CSI

[0068] When performing precoding, the access network device precodes downlink data using a precoding matrix. To obtain the precoding matrix, the access network device needs to acquire the CSI of the downlink channel and determine the precoding matrix based on the CSI. In a wireless communication system, CSI feedback is information used to describe the channel attributes of a communication link, reported from the data receiving end (e.g., a terminal device) (not limited to data transmitted on the physical downlink shared channel (PDSCH)) to the transmitting end (e.g., the access network device). The higher the accuracy of the CSI feedback by the terminal device, the more complete the feedback channel information, and the more accurate the precoding matrix determined by the access network device based on the CSI. As a result, the downlink spatial multiplexing performance is improved, the received signal-to-interference-plus-noise ratio of the terminal device is higher, and the system capacity is larger. CSI includes one or more pieces of information such as a downlink channel matrix, a precoding matrix indicator (PMI), a rank indicator (RI), or a channel quality indicator (CQI). The above content included in CSI is merely an example for explanation and does not constitute a limitation of this application.

[0069] 3. Neural Network (NN)

[0070] A neural network is a specific implementation form of machine learning technology. According to the universal approximation theorem, a neural network can theoretically approximate any continuous function, and the neural network will have the ability to learn any mapping. In traditional communication systems, rich expertise was required for the design of communication modules. However, in a deep learning communication system based on neural networks, by automatically discovering implicit pattern structures from a large amount of dataset and establishing the mapping relationship between data, performance superior to traditional modeling methods can be obtained.

[0071] For example, a deep neural network (DNN) is a neural network with a large number of layers. Depending on different network structures and / or usage scenarios, DNN can include multi-layer perceptron (MLP), convolutional neural network (CNN), recurrent neural network (RNN), etc. The specific form of DNN is not limited in this application.

[0072] Figure 2 is a diagram of an application framework in a communication system. A data source is configured to store training data and inference data. A model training host analyzes or trains the training data provided by the data source to obtain an AI model and deploys the AI model to a model inference host. The model inference host uses the AI model to perform inferences based on the inference data provided by the data source and obtains the inference results. The inference results are uniformly planned by an actor entity and sent to one or more actor objects (e.g., network entities) for execution.

[0073] 4. Reference encoder model and reference decoder model

[0074] To increase system capacity and reduce the overhead of CSI feedback, CSI may be fed back by a deep learning-based CSI compression method. The CSI compression and feedback technology based on deep learning is to perform CSI compression and feedback by using a CNN-based auto-encoder (AE) model. The AE model includes an AI encoder model and an AI decoder model used together. The AI encoder model and the AI decoder model may be AI models obtained by analyzing or training the training data provided from a data source. In this application, the AI encoder model is abbreviated as the encoder and the AI decoder model is abbreviated as the decoder. For example, as shown in Figure 3, after preprocessing the downlink channel data through the encoder, the terminal device encodes the downlink channel data through the encoder to obtain an encoded bit stream, and then quantizes the bit stream through a quantizer to obtain a quantized bit stream. The terminal device can feedback the quantized bit stream to the access network device. Correspondingly, the access network device processes the received bit stream through an inverse quantizer, inputs the bit stream into the decoder for decoding, and obtains the restored downlink channel data.

[0075] In this application, the entity that trains the AI encoder model and the AI decoder model may be an access network device, a terminal device, or a third-party network entity. For example, when the entity that trains the AI encoder model and the AI decoder model is an access network device, the access network device distributes the trained AI encoder model and the trained AI decoder model to the terminal device, and the terminal device may directly use the received network models, the trained AI encoder model and the trained AI decoder model, or may use the trained AI encoder model and the trained AI decoder model after performing specific adjustments. When the entity that trains the AI encoder model and the AI decoder model is a terminal device, the terminal device can upload the trained AI encoder model and the trained AI decoder model to the network-side device. When the entity that trains the AI encoder model and the AI decoder model is a third-party network entity, the access network device or the terminal device can download the AI encoder model and the AI decoder model from the third-party network entity.

[0076] In general AI-based CSI compression and quantization, both an encoder and a decoder exist. After the terminal device side executes the encoding operation, the access network device side needs to execute the corresponding decoding operation. In this case, the terminal device and the access network device need to know the features learned from each other. The devices do not need to completely know each other's network structures and network parameters, that is, specific implementation methods, but only need to know the functions implemented by each other. In a possible implementation, a reference model is used. In other words, a set of reference models including a reference encoder and a reference decoder is defined by the protocol. Both the terminal device and the access network device can obtain the reference encoder and the reference decoder based on the description of the protocol. The terminal device can train an encoder that matches the reference decoder based on the reference decoder, and the access network device can train a decoder that matches the reference encoder based on the reference encoder.

[0077] The terminal device feeds back the bitstream encoded by the encoder to the access network device. Since the terminal device can only determine the reference decoder and cannot determine the decoder trained by the access network device based on the reference decoder, the terminal device cannot learn the downlink channel data finally restored by the access network device. Also, in this method, the access network device needs to determine the CSI of the downlink channel based on the restored downlink channel data. Therefore, the overhead of the access network device is high. Especially when a large number of terminal devices access the access network device, the load and power consumption of the access network device increase.

[0078] Therefore, the present application provides a technical solution to solve the above problems.

[0079] In the present application, ordinal numbers such as "first" and "second" are used to distinguish a plurality of objects, and are not used to limit the size, content, order, time series, application scenario, priority, importance, etc. of the plurality of objects. For example, the first instruction information and the second instruction information may be the same instruction information or different instruction information. Also, this type of name does not indicate that the sizes, transmission modes, contents shown, priorities, application scenarios, importance, etc. of the two pieces of display information are different.

[0080] The following describes the method provided in the present application with reference to the accompanying drawings. The steps or operations included in the method are merely examples. In the present application, other operations or variations of various operations may be further executed. Also, it is possible to execute the steps in an order different from that described in the present application, and it may not be necessary to execute all the operations.

[0081] In the following procedure, the interaction between the terminal device and the access network device is mainly described as an example. When applying the technical solution provided in the present application to the interaction between other devices, adaptation and adjustment can be performed according to the method provided in the present application.

[0082] FIG. 4 is a schematic flowchart of a communication method according to an embodiment of the present application. The method includes the following steps.

[0083] S401: The access network device determines a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in the terminal device.

[0084] In the present application, a reference encoder and a reference decoder are agreed upon between the terminal device and the access network device. The reference decoder is a decoder that matches the reference encoder, and the first decoder is obtained by training based on the reference encoder. The second decoder is the reference decoder, and since the access network device can determine the performance of the second decoder, the first performance difference can be determined.

[0085] In the present application, the first performance difference may be in decibels (dB) or may be a linear value. This is not limited in the present application.

[0086] S402: The access network device transmits the first information to the terminal device. Correspondingly, the terminal device receives the first information from the network device.

[0087] The first information is used to determine the first performance difference.

[0088] In the present application, the difference between the performance of the first decoder and the performance of the second decoder, that is, the first performance difference, may be related to the value of the rank of the channel or may be independent of the value of the rank.

[0089] If the first performance difference is independent of the value of the rank, the first performance difference does not change when the values of the rank are different. In other words, different values of the rank correspond to the same first performance difference. If the first performance difference is related to the value of the rank, different values of the rank correspond to different first performance differences. In this case, when the maximum value of the rank is N, the channel includes N streams, the first information indicates N first performance differences, each first performance difference corresponds to one stream, and N is an integer greater than 0.

[0090] In the present application, when the first performance difference is independent of the value of the rank, the first information can be implemented in the following manner.

[0091] In the first implementation, the first information is the first performance difference. For example, the first performance difference is 0.5 and the first information is 0.5.

[0092] In this implementation, the terminal device can directly determine the first performance difference based on the first information. This implementation has low complexity and can reduce the complexity of the system.

[0093] In the second implementation, the first information and the first performance difference satisfy the relationship of a preset function.

[0094] In this implementation, the terminal device uses the first information as the input value of a preset function, and uses the output value obtained by using the first information as the input value as the first performance difference.

[0095] For example, the preset function can satisfy the form of y = f(PD_index, a). y represents the first performance difference, PD_index represents the first information, a represents a step, the value of a is preset, or for example, it may be configured by an access network device such as a = 0.5. The specific form of f(PD_index, a) is not limited in this application. For example, the preset function may be y = PD_index + a. In this case, when PD_index = 0, the first performance difference is a, and when PD_index = 1, the first performance difference is 1 + a. Other cases can be analogized.

[0096] The above are merely examples, and the preset function may alternatively be in other forms. The description of each example is omitted.

[0097] This implementation can reduce the overhead for transmitting the first information and improve system efficiency.

[0098] In the third implementation, each performance difference corresponds to one indicator, and the first information is the indicator of the first performance difference.

[0099] In this implementation, the correspondence between the performance difference and the indicator may be agreed upon by a protocol or configured by an access network device. This is not limited in this application.

[0100] In this implementation, the terminal device acquires the first information and uses the performance difference with the first information as the indicator as the first performance difference.

[0101] For example, a plurality of performance difference indicators are defined in the protocol. For example, the relationship between the performance difference and the indicators can be shown in Table 1. Here, assume that 4 bits are used as an example of the indicator. In the present application, the number of bits included in the indicator is not limited. [Table 1]

[0102] Referring to Table 1, when the first information received by the terminal device is 0000, the first performance difference is 0.5. Or, when the first information received by the terminal device is 1111, the first performance difference is 0. Other cases will not be described in detail.

[0103] This implementation is flexible and can reduce the overhead for transmitting the first information.

[0104] In the fourth implementation, the access network device pre-configures the reference performance for the terminal device. The access network device indicates the performance difference between the performance of the first decoder and the pre-set reference performance based on the first information. The terminal device can determine the first performance difference based on the second performance difference and the reference performance.

[0105] In this implementation, when the first information is the second performance difference, the terminal device can use the sum of the first information and the reference performance as the first performance difference.

[0106] When the first information and the second performance difference satisfy the relationship of a pre-set function, the terminal device uses the first information as the input value of the pre-set function, uses the output value obtained by using the first information as the input value as the second performance difference, and uses the sum of the second performance difference and the reference performance as the first performance difference.

[0107] When the first information is an indicator of the second performance difference, the terminal device can determine the second performance difference based on the first information and use the sum of the second performance difference and the reference performance as the first performance difference.

[0108] For example, the reference performance is PD_base, and the relationship between the performance difference and the index defined in the protocol can be shown in Table 2. [[Table 2]]

[0109] Referring to Table 2, when the first information received by the terminal device is 0000, the second performance difference is 0.1, and the first performance difference is 0.1 + PD_base. Or, when the first information received by the terminal device is 0011, the second performance difference is 0.4, and the first performance difference is 0.4 + PD_base. Other cases will not be described in detail.

[0110] In this application, when the first performance difference is related to the value of the rank, the first information can be implemented in the following way.

[0111] In the fifth implementation, the first information includes N first performance differences, and different rank values correspond to different first performance differences. For example, since the rank value represents the amount of streams in the channel, when the rank value is X, the rank corresponds to X first performance differences, and each of the X streams corresponds to one of the X first performance differences. For example, the first information includes two first performance differences of 0.5 and 0.75 respectively. When the rank value is 1, the first performance difference is 0.5. When the rank value is 2, the channel includes two streams. The first performance difference corresponding to the first stream is 0.5, and the first performance difference corresponding to the second stream is 0.75.

[0112] In the sixth implementation, the first information and the first performance difference satisfy the relationship of a preset function.

[0113] For example, the preset function can satisfy the form of y = f(PD_index, a). y represents the first performance difference, PD_index represents the first information, a represents the step, the value of a is preset, or a is configured by the access network device, and different rank values correspond to different values of a.

[0114] For example, when the rank value is 1, the value of a is 0.25, and the pre-set function is y = f(PD_index, 0.25). Or, when the rank value is 2, the value of a is 0.5, and the pre-set function is y = f(PD_index, 0.5). For example, the pre-set function may be y = PD_index + a. When PD_index = 0 and the rank value is 1, the first performance difference is 0.25 = 0 + 0.25. When PD_index = 0 and the rank value is 2, the first performance difference is 0.5 = 0 + 0.5. For other cases, it can be inferred by analogy.

[0115] The above are merely examples, and the pre-set function may alternatively be in other forms. The description of each example is omitted.

[0116] In the seventh implementation, the first information is an indicator corresponding to N first performance differences, and each performance difference corresponds to a different rank value.

[0117] In this implementation, the correspondence between the performance difference and the indicator may be agreed upon by a protocol or may be configured by an access network device. This is not limited in the present application.

[0118] In this implementation, since one indicator corresponds to N first performance differences, the overhead of the first information can be reduced.

[0119] For example, let the maximum value of the rank be 2 and the amount of the stream in the channel be 2. The relationship between the performance difference and the indicator can be shown in Table 3.

Table 3

[0120] Referring to Table 3, if the first information received by the terminal device is 0000, when the rank is 1, the first performance difference is 0.5, and when the rank is 2, the first performance difference corresponding to the second stream is 0.25. Details for other cases are not described.

[0121] In the eighth implementation, the first information is an indicator corresponding to the first performance difference, and values of different ranks correspond to different first performance difference indicators.

[0122] In this implementation, the correspondence between the performance difference and the indicator may be agreed upon by a protocol or may be configured by an access network device. This is not limited in the present application.

[0123] In this implementation, since one indicator corresponds to one first performance difference, the flexibility in indicating the performance difference can be enhanced.

[0124] For example, let the maximum value of the rank be 2 and the amount of the stream in the channel be 2. The relationship between the performance difference and the indicator can be shown in Table 4. [Table 4]

[0125] Referring to Table 4, when the first information received by the terminal device is 0000, the first performance difference is 0.5 and the corresponding rank is 1. Or, when the first information received by the terminal device is 1000, the first performance difference is 0.25 and the corresponding rank is 2.

[0126] The above are merely examples. There may be other implementations of the first information. This is not limited to the present application and will not be described one by one here.

[0127] S403: The terminal device decodes the encoded bit stream corresponding to the channel data via the second decoder to obtain channel information.

[0128] In the present application, the terminal device may measure a reference signal from an access network device and obtain channel data. The channel data can represent information regarding a downlink channel matrix. The terminal device may encode the channel data via a reference encoder and obtain an encoded bit stream. The channel information obtained by the terminal device by decoding the encoded bit stream via a second decoder is information for predicting that the access network device decodes the encoded bit stream.

[0129] S404: The terminal device determines a first value of the rank based on the first performance difference and the channel information.

[0130] In the present application, the terminal device determines a channel indicator corresponding to each of the N values of the rank based on the first performance difference and the channel information, and uses the value of the optimal channel indicator among the channel indicators corresponding to the N values as the first value.

[0131] For example, the channel indicator is throughput. Assume that the maximum value of the rank is 2. In this case, the value of the rank may be 1 or 2. The terminal device calculates the throughput of the downlink channel when the rank is 1 and calculates the throughput of the downlink channel when the rank is 2. If the throughput of the downlink channel is the maximum when the rank is 1, the first value is 1. If the throughput of the downlink channel is the maximum when the rank is 2, the first value is 2. The maximum value of the rank is the larger of the number of transmission ports of the access network device and the number of reception ports of the terminal device.

[0132] The method for calculating throughput is not limited in the present application. For example, assume that the rank is 2, that is, the number of streams corresponding to the downlink channel between the terminal device and the access network device is 2. The terminal device can determine the codewords of the precoding matrix corresponding to the two streams based on the channel data. Assume that the two codewords are P1 and P2 respectively. The terminal device may separately calculate the SINR corresponding to the two streams for the two streams. For example, the SINR of the first stream in the two streams is represented as SINR1, the SINR of the second stream is represented as SINR2, and SINR1 and SINR2 can satisfy the following formula.

Number

[0133] H represents the channel data, and the following formula represents the conjugate transpose operation:

Number

[0134] In addition, the terminal device may separately determine the throughput of the two streams based on SINR1 and SINR2. There are many methods for calculating throughput. For example, the throughput can be calculated using Shannon's formula. Specifically, the formula is as follows:

Number

[0135] B represents the bandwidth of the channel.

[0136] Finally, the throughput throughput1 corresponding to SINR1 and the throughput throughput2 corresponding to SINR2 are added to obtain the throughput of the downlink channel when the rank value is 2.

[0137] In the present application, the terminal device can further determine the CQI corresponding to the first value. For example, there is a mapping relationship between CQI and SINR, and the mapping relationship may be configured by a protocol or in another way. The terminal device determines the SINR corresponding to the first value so that the terminal device can determine the CQI corresponding to the first value based on the mapping relationship between CQI and SINR.

[0138] In the present application, the terminal device may further determine the decoding performance of the first decoder based on the first performance difference. For example, the terminal device may calculate the first correlation between the input P of the reference encoder and the output Q of the second decoder, and the first correlation corr1 may satisfy the following form:

Number

[0139] abs() represents the absolute value operation. The value range of corr1 is [0, 1], and the larger the value of corr1, the better the decoding performance of the first decoder.

[0140] Furthermore, the terminal device determines the second correlation between the input of the reference encoder and the output of the first decoder based on the first performance difference and the first correlation. For example, when the first performance difference is PD, the second correlation corr2 satisfies the following form:

Number

[0141] When the terminal device determines that the second correlation is equal to or less than a preset threshold value, the terminal device may transmit instruction information to the access network device. The instruction information indicates the second correlation of the first decoder. Based on the instruction information, the access network device determines that the performance of the first decoder is poor, and may execute further training for the first decoder to optimize the performance of the first decoder.

[0142] S405: The terminal device transmits a rank indicator and a channel quality indicator corresponding to the first value to the access network device. Correspondingly, the access network device receives the first value of the rank and the channel quality indicator corresponding to the first value from the terminal device.

[0143] The rank indicator indicates the first value. The rank indicator may be the first value or an indicator of the first value. This is not limited in the present application.

[0144] In the present application, the terminal device and the access network device may further transmit a coded bit stream corresponding to the channel data.

[0145] The access network device may determine the channel data based on the coded bit stream. Further, the access network device may determine a precoding matrix based on one or more of the first value of the rank, the channel quality indicator corresponding to the first value, and the channel data. When transmitting downlink data to the terminal device, the access network device may precode the downlink data using the precoding matrix to improve the signal quality of the downlink signal and increase the throughput of the downlink.

[0146] According to the method provided in the present application, the terminal device determines the first value of the rank based on the first performance difference fed back by the access network device. As a result, the first value fed back by the terminal device to the access network device better matches the precoding matrix determined by the access network device, improving the accuracy and correctness of the feedback.

[0147] In the above embodiment provided in the present application, the method provided in the embodiment of the present application is described from the perspective of the interaction between devices. In order to realize the functions in the method provided in the embodiment of the present application, the access network device or the terminal device includes a hardware structure and / or a software module, and can realize the functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether a certain function among the above functions is executed using a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the specific application and design constraints of the technical solution.

[0148] In the embodiment of the present application, the module division is an example and is merely a logical function division. In actual implementation, another division method may be used. Furthermore, the functional modules in the embodiment of the present application may be integrated into one processor, or may physically exist alone, or two or more modules may be integrated into one module. The integrated module may be implemented in the form of hardware or in the form of a software functional module.

[0149] Similar to the aforementioned concept, as shown in FIG. 5, embodiments of the present application further provide a communication device. The communication device is configured to implement the functions of the access network device or the terminal device in the aforementioned method. For example, the communication device may be a software module or a chip system. In the present embodiment of the present application, the chip system may include a chip, or may include a chip and another individual component. The communication device 500 may include a processing unit 501 and a communication unit 502.

[0150] In an embodiment of the present application, the communication unit, also referred to as a transceiver unit, may be configured to perform the transmission step and the reception step of the access network device or the terminal device in the embodiment of the aforementioned method, respectively.

[0151] The following will describe in detail the communication device provided in the embodiments of the present application with reference to FIGS. 5 and 6. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments. Therefore, for the content not described in detail, refer to the method embodiments. For the sake of brevity, the details will not be described again here.

[0152] The communication unit is also referred to as an interface circuit, a transceiver machine, a transceiver device, etc. The processing unit may also be referred to as a processor, a processing board, a processing module, a processing device, etc. Optionally, a component within the communication unit 502 configured to implement the reception function may be considered as a reception unit, and a component within the communication unit 502 configured to implement the transmission function may be considered as a transmission unit. In other words, the communication unit 502 includes a reception unit and a transmission unit. The communication unit may sometimes also be referred to as a transceiver machine, an interface circuit, a transceiver circuit, etc. The reception unit may sometimes also be referred to as a reception machine, a receiver, a reception circuit, etc. The transmission unit may sometimes also be referred to as a transmission machine, a transmitter, a transmission circuit, etc.

[0153] When the communication device 500 executes the functions of the terminal device in the procedure shown in FIG. 4 of the foregoing embodiment, the communication unit is configured to receive first information from the access network device, and the first information is used to determine a first performance difference between the performance of the first decoder in the access network device and the performance of the second decoder in the terminal device. The processing unit is configured to decode the encoded bitstream corresponding to the channel data via the second decoder, obtain channel information, and determine a first value of the rank based on the first performance difference and the channel information. The communication unit is configured to transmit a rank indicator and a channel quality indicator corresponding to the first value to the access network device, and the rank indicator indicates the first value.

[0154] When the communication device 500 executes the functions of the access network device in the procedure shown in FIG. 4 of the foregoing embodiment, the processing unit is configured to determine a first performance difference between the performance of the first decoder in the access network device and the performance of the second decoder in the terminal device. The communication unit is configured to transmit the first information to the terminal device, and the first information is used to determine the first performance difference. The communication unit receives, from the terminal device, a rank indicator and a channel quality indicator corresponding to the first value. The rank indicator indicates the first value, and the first value is determined based on the first performance difference and the channel information. The channel information is obtained by decoding the encoded bitstream corresponding to the channel data via the second decoder.

[0155] The above are merely examples. The processing unit 501 and the communication unit 502 may further execute other functions. For more detailed descriptions, refer to the relevant descriptions in the embodiment of the method shown in FIG. 4. Details are not described here again.

[0156] FIG. 6 shows a communication device according to an embodiment of the present application. The communication device shown in FIG. 6 may be an implementation of the hardware circuit of the communication device shown in FIG. 5. The communication device is applicable to the above-described flowchart and executes the functions of the terminal device or the access network device in the above-described method embodiments. For ease of explanation, FIG. 6 shows only the main components of the communication device.

[0157] As shown in FIG. 6, the communication device 600 includes a processor 610 and an interface circuit 620. The processor 610 and the interface circuit 620 are coupled to each other. It should be understood that the interface circuit 620 may be an interface circuit, a pin, an interface circuit, or an input / output interface. Optionally, the communication device 600 may further include a memory 630 configured to store instructions executed by the processor 610, store input data required for the processor 610 to execute instructions, or store data generated after the processor 610 executes instructions.

[0158] When the communication device 600 is configured to implement the method shown in FIG. 4, the processor 610 is configured to implement the function of the processing unit 501, and the interface circuit 620 is configured to implement the function of the communication unit 502.

[0159] When the communication device is a chip used in a terminal device, the chip in the terminal device realizes the function of the terminal device in the above-described method embodiments. The chip in the terminal device receives information from another module (for example, a radio frequency module or an antenna) in the terminal device, and the information is transmitted from the access network device to the terminal device. Alternatively, the chip in the terminal device transmits information to another module (for example, a radio frequency module or an antenna) in the terminal device, and the information is transmitted from the terminal device to the access network device.

[0160] When the communication device is a chip used in an access network device, the chip in the access network device realizes the functions of the access network device in the above-described method embodiments. The chip in the access network device receives information from another module (e.g., a radio frequency module or an antenna) within the access network device, and the information is transmitted to the access network device by a terminal device. Alternatively, the chip in the access network device transmits information to another module (e.g., a radio frequency module or an antenna) within the access network device, and the information is transmitted to the terminal device by the access network device.

[0161] It should be understood that the processor in the embodiments of the present application may be a central processing unit, or may be any other general-purpose processor, digital signal processor, application-specific integrated circuit, or other programmable logic element, transistor logic element, hardware component, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0162] The memory in the embodiments of the present application may be a random access memory, flash memory, read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, register, hard disk, removable hard disk, or any other form of storage medium well-known in the art.

[0163] Those skilled in the art should understand that the embodiments of the present application may be provided as a method, system, or computer program product. Therefore, the present application may use forms of embodiments that are only hardware, only software, or a combination of software and hardware. Furthermore, the present application may use the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical memory, etc.) containing computer-usable program code.

[0164] This application has been described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to the application. It should be understood that computer program instructions may be used to implement each procedure and / or each block in the flowchart and / or block diagram, and / or combinations of procedures and / or blocks in the flowchart and / or block diagram. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or another programmable data processing apparatus to generate a machine for implementing specific functions in one or more procedures in the flowchart and / or one or more blocks in the block diagram.

[0165] Alternatively, these computer program instructions may be stored in a computer-readable memory and can direct a computer or other programmable data processing apparatus to operate in a specific manner. As a result, the instructions stored in the computer-readable memory generate something that includes an instruction device. The instruction device implements specific functions in one or more procedures in the flowchart and / or one or more blocks in the block diagram.

[0166] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the scope of this application. This application is intended to cover these changes and modifications of this application if they are within the scope of the claims of this application and the scope of their equivalent technologies.

Claims

1. A communication method applied to a terminal device side, comprising: receiving first information from an access network device, the first information being used to determine a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in the terminal device; decoding, via the second decoder, a coded bitstream corresponding to channel data to obtain channel information; determining a first value of a rank based on the first performance difference and the channel information; transmitting a rank indicator and a channel quality indicator corresponding to the first value to the access network device, the rank indicator indicating the first value; A method comprising the above steps.

2. The method further comprises: transmitting, to the access network device, the coded bitstream corresponding to the channel data. The method according to claim 1, further comprising the above step.

3. The first information and the first performance difference satisfy a relationship of a preset function. The method further comprises: using an output value of the preset function obtained by using the first information as an input value as the first performance difference. The method according to claim 1 or 2, further comprising the above step.

4. The first information is an indicator of the first performance difference. The method further comprises: using, as the first performance difference, a performance difference with the first information as an indicator. The method according to claim 1 or 2, further comprising the above step.

5. The first information is an indicator of a second performance difference, the second performance difference being a performance difference between the performance of the first decoder and a preset reference performance. The method further comprises: determining the first performance difference based on the second performance difference and the reference performance. The method according to claim 1 or 2, further comprising the above step.

6. The method according to any one of claims 1 to 5, wherein a maximum value of the rank is N, the first information indicates N first performance differences, and N is an integer greater than 0.

7. The step of determining a first value of a rank based on the first performance difference and the channel information comprises: determining, based on the first performance difference and the channel information, a channel indicator corresponding to each of the N values of the rank, where N is an integer greater than 0. using, as the first value, the value of the optimal channel indicator among the channel indicators corresponding to the N values; The method according to any one of claims 1 to 6, including this.

8. A communication method applied to the access network device side, determining a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in the terminal device; transmitting first information to the terminal device, where the first information is used to determine the first performance difference; receiving, from the terminal device, a rank indicator and a channel quality indicator corresponding to the first value, where the rank indicator indicates the first value, the first value is determined based on the first performance difference and channel information, and the channel information is obtained by decoding a coded bitstream corresponding to channel data via the second decoder; A method including this.

9. The method is transmitting, to the access network device, the coded bitstream corresponding to the channel data; The method according to claim 8, further including this.

10. The first information and the first performance difference satisfy a relationship of a preset function, and when the input value of the preset function is the first information, the output value of the preset function is the first performance difference. The method according to claim 8 or 9.

11. The first information is an index of the first performance difference. The method according to claim 8 or 9.

12. The first information is an indicator of a second performance difference, the second performance difference is a performance difference between the performance of the first decoder and a preset reference performance, and the first performance difference is determined based on the second performance difference and the reference performance. The method according to claim 8 or 9.

13. The maximum value of the rank is N, the first information indicates N first performance differences, and N is an integer greater than 0. The method according to any one of claims 8 to 12.

14. The first value is the value of the optimal channel indicator among the channel indicators corresponding to the N values of the rank, N is an integer greater than 0, and the channel indicator corresponding to each of the N values of the rank is determined based on the first performance difference and the channel information. The method according to any one of claims 8 to 13.

15. A communication device, A communication unit configured to receive first information from an access network device, where the first information is used to determine a first performance difference between the performance of a first decoder in the access network device and the performance of a second decoder in a terminal device. A processing unit, Decoding a coded bitstream corresponding to channel data via the second decoder to obtain channel information, A processing unit configured to determine a first value of a rank based on the first performance difference and the channel information, Including, The communication unit is configured to transmit a rank indicator and a channel quality indicator corresponding to the first value to the access network device, and the rank indicator indicates the first value. The communication device.

16. A communication device, A processing unit configured to determine a first performance difference between the performance of a first decoder in an access network device and the performance of a second decoder in a terminal device, A communication unit, Transmitting first information to the terminal device, where the first information is used to determine the first performance difference, Receiving from the terminal device a rank indicator and a channel quality indicator corresponding to the first value, the rank indicator indicating the first value, the first value being determined based on the first performance difference and channel information, and the channel information being obtained by decoding a coded bitstream corresponding to channel data via the second decoder. The communication unit is configured as such. A communication device including.

17. A computer-readable storage medium, where the storage medium stores a computer program or instructions, and when the computer program or the instructions are executed on a computer, the method according to any one of claims 1 to 14 is implemented. The computer-readable storage medium.

18. A computer program product comprising a computer program or instructions, wherein when the computer program or instructions are executed on a computer, the method according to any one of claims 1 to 14 is executed.

19. A communication device comprising a processor and a communication circuit, wherein the processor is configured to execute the method according to any one of claims 1 to 14.

20. A communication system comprising the communication device according to claim 15 and the communication device according to claim 16.

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