A communication method, a communication device, and a communication system

Abstract

The application provides a communication method, a communication device and a communication system, and relates to the technical field of communication. The communication method comprises the following steps: a network device sends downlink control information for scheduling an uplink data channel to a terminal device, wherein the uplink data channel contains transmission data of one or more transmission layers, a frequency domain range of the uplink data channel contains a plurality of uplink subbands, the downlink control information carries first information and second information, the first information is used for indicating a reference precoding matrix, and the second information is used for determining a phase difference between any uplink subband in the plurality of uplink subbands and an uplink subband corresponding to the reference precoding matrix in the same transmission layer; and the terminal device determines a precoding matrix corresponding to the uplink subband according to the reference precoding matrix and the second information, and transmits the uplink data channel to the network device. Therefore, the precoding matrix corresponding to the plurality of uplink subbands does not need to be indicated by the plurality of downlink control information one by one, and the resource overhead required for downlink control information indication is reduced.

Description

Technical Field

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

[0002] In existing wireless communication technologies, when a terminal device sends uplink data to the network side through an uplink data channel, the terminal device precodes the uplink data before sending it to improve the reliability and capacity of the uplink data channel.

[0003] Currently, terminal devices use wideband precoding for uplink data precoding, meaning that all uplink sub-bands within the frequency domain of the uplink data channel use the same precoding matrix. However, as the number of antennas on terminal devices increases, the channel differences experienced by signals at different frequency locations become greater. Therefore, using wideband precoding for uplink data precoding by terminal devices can negatively impact system performance. Thus, determining how to indicate the precoding matrices corresponding to multiple uplink sub-bands is a problem that urgently needs to be solved. Summary of the Invention

[0004] This application provides a communication method, communication device, and communication system. The network device indicates a reference precoding matrix and the frequency offset of each sub-band to the terminal device, eliminating the need to individually indicate the precoding matrix corresponding to each of the multiple uplink sub-bands via downlink control information, thus reducing the resource overhead required for downlink control information indication.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, a communication method is provided, applied to a terminal device or a chip or functional entity / unit in the terminal device. The method may include: the terminal device receiving downlink control information from a network device for scheduling an uplink data channel, the uplink data channel containing transmission data of one or more transmission layers, the uplink data channel containing multiple uplink sub-bands in its frequency domain, the downlink control information carrying first information and second information, the first information being used to indicate a reference precoding matrix, and the second information being used to determine the phase difference between any uplink sub-band among the multiple uplink sub-bands and the uplink sub-band corresponding to the reference precoding matrix in the same transmission layer; after determining the precoding matrix corresponding to the multiple uplink sub-bands according to the reference precoding matrix and the second information, the terminal device transmitting the uplink data channel to the network device.

[0007] In this implementation, the network device does not need to carry the index information of the precoding matrix corresponding to each uplink subband in the downlink control information indication to the terminal device. It can determine the precoding matrix corresponding to all uplink subbands simply by using the reference precoding matrix and the phase difference between the transport layer in all uplink subbands and the same transport layer in the uplink subband corresponding to the reference precoding matrix. Since the phase difference indicated by the second information is less than the number of uplink subbands included in the frequency domain of the uplink data channel, and the overhead required to indicate a phase difference is generally less than the overhead required to indicate a precoding matrix, the overhead required for downlink control information indication is reduced. Furthermore, the terminal device uses the precoding matrix corresponding to each uplink subband to precode the uplink data transmitted in the uplink subband, thereby enabling the precoded uplink data to better match the channel characteristics, thus improving data transmission quality and system performance.

[0008] In one possible scenario of the first aspect, the second information is used to indicate the phase corresponding to each of the at least one transport layers.

[0009] In this implementation, after the terminal device receives the reference precoding matrix indicated by the first information and the phase indicated by the second information, it can determine the precoding matrix corresponding to the uplink subband. This eliminates the need for downlink control information to indicate the precoding matrices corresponding to multiple uplink subbands separately, thereby reducing the overhead required for downlink control information indication.

[0010] In another possible scenario of the first aspect, the second information includes index information of the phase corresponding to each transport layer in at least one transport layer; or, the second information includes index information of the phase corresponding to the remaining transport layers in at least one transport layer, excluding the reference transport layer.

[0011] In this implementation, when the uplink data channel contains transmission data from multiple transmission layers, the second information may include the index information of the phase corresponding to each transmission layer. The terminal device can then determine the precoding matrix corresponding to different transmission layers of the uplink subband based on the reference precoding matrix and the phase corresponding to different transmission layers.

[0012] In another possible scenario of the first aspect, the second information includes index information of the phase corresponding to the reference transport layer and a first differential phase of at least one transport layer, the first differential phase being the difference between the phase corresponding to the transport layer and the phase corresponding to the reference transport layer.

[0013] In this implementation, since the overhead required for the second information to indicate the first differential phase is less than the overhead required for the second information to indicate the phase corresponding to the reference transport layer, the second information indicates the phase corresponding to the reference transport layer and the first differential phase corresponding to at least one of the multiple transport layers, thus reducing the resource overhead required for the second information.

[0014] In another possible scenario of the first aspect, the second information is used to indicate a vector corresponding to each of at least one transport layer; the vector corresponding to the transport layer includes multiple elements, the multiple elements corresponding to multiple uplink subbands, and one element is used to indicate the phase difference between the uplink subband corresponding to the element and the uplink subband corresponding to the reference precoding matrix in the transport layer.

[0015] In another possible scenario of the first aspect, the second information includes a vector-related indication corresponding to each of the multiple transport layers; or, the second information includes a vector-related indication corresponding to each transport layer other than the reference transport layer.

[0016] In this implementation, when the uplink data channel contains transmission data from multiple transmission layers, the second information can indicate the vector-related indication for each transmission layer. The terminal device can then determine the precoding matrix corresponding to different transmission layers in the uplink subband based on the reference precoding matrix and the vectors corresponding to different transmission layers.

[0017] In another possible scenario of the first aspect, the vector corresponding to each transport layer is one of a predefined set of vectors.

[0018] In this implementation, because the predefined vectors have a fixed vector format, processing time and transmission overhead can be reduced.

[0019] In another possible scenario of the first aspect, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the terminal device can use as indicated by the network device.

[0020] In this implementation, the number of transport layers included in the uplink data channel is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use. The number of phases or vectors indicated by the second information is determined based on the number of transport layers. Therefore, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

[0021] In another possible embodiment of the first aspect, the method may further include: the terminal device determining, based on the second information, the phase difference between any uplink subband among a plurality of uplink subbands and the uplink subband corresponding to the reference precoding matrix in the same transport layer; and for any uplink subband, determining the precoding matrix of the uplink subband based on the phase difference between the reference precoding matrix and the uplink subband.

[0022] In another possible scenario of the first aspect, the precoding matrix of the uplink subband is determined based on the phase difference between the reference precoding matrix and the corresponding uplink subband, including: second information indicating at least one phase, the precoding matrix used by the uplink subband being determined based on the product of the reference precoding matrix and first coefficients, the first coefficients being determined based on the phase and index information of the uplink subband; or, the second information indicating at least one vector, the precoding matrix used by the uplink subband being determined based on the product of the reference precoding matrix and second coefficients, the second coefficients being determined based on the vector and index information of the uplink subband.

[0023] In this implementation, after the terminal device receives the reference precoding matrix indicated by the first information and the phase or vector indicated by the second information, it can determine the precoding matrix corresponding to the uplink sub-band. This eliminates the need for the downlink control information to indicate the precoding matrices corresponding to multiple uplink sub-bands separately, thereby reducing the overhead required for downlink control information indication.

[0024] In another possible scenario of the first aspect, the downlink control information also carries third information, which is used to indicate the initial phase of the precoding matrix corresponding to the multiple uplink subbands.

[0025] In this implementation, since the initial phase of the precoding matrix corresponding to the uplink subband may be non-zero, the network device can be configured to carry third information in the downlink control information to indicate the initial phase of the precoding matrix corresponding to the uplink subband. By referring to the initial phase and the phase indicated by the first and second information, the accuracy of determining the precoding matrix corresponding to the uplink subband is improved.

[0026] In another possible embodiment of the first aspect, the method may further include: the terminal device determining, based on the second information, the phase difference between any uplink subband among a plurality of uplink subbands and the uplink subband corresponding to the reference precoding matrix in the same transport layer; for any uplink subband, determining the final phase corresponding to the uplink subband based on the initial phase corresponding to the uplink subband and the phase difference corresponding to the uplink subband; and determining the precoding matrix of the uplink subband based on the product of the reference precoding matrix and the third coefficient corresponding to the uplink subband, wherein the third coefficient is determined by the final phase corresponding to the uplink subband.

[0027] In this implementation, since the initial phase of the precoding matrix corresponding to the uplink subband is not 0, the terminal device can determine the precoding matrix corresponding to the uplink subband based on the reference precoding matrix indicated by the first information, the phase difference determined by the second information, and the initial phase indicated by the third information.

[0028] In another possible scenario of the first aspect, where the initial phase includes initial phases corresponding to multiple transport layers, the third information includes index information of the initial phase of each transport layer.

[0029] In this implementation, after receiving the third information carried in the downlink control information, the terminal device can determine the initial phase of each transport layer based on the index information of the initial phase of each transport layer included in the third information. In this way, the terminal device can determine the precoding matrix corresponding to different transport layers in the uplink subband based on the initial phase of each transport layer.

[0030] In the case where the initial phase includes the initial phases corresponding to multiple transmission layers, the third information includes the initial phase of the reference transmission layer and the second differential phase of at least one of the multiple transmission layers, wherein the second differential phase is the difference between the initial phase of the transmission layer and the initial phase of the reference transmission layer.

[0031] In this implementation, since the overhead required for the second information to indicate the second differential phase is less than the overhead required for the second information to indicate the initial phase corresponding to the reference transport layer, the second information indicates the initial phase corresponding to the reference transport layer and the second differential phase corresponding to at least one of the multiple transport layers, thus reducing the resource overhead required for the second information.

[0032] In another possible scenario of the first aspect, the first information includes index information of the reference precoding matrix.

[0033] In this implementation, after receiving the first information carried by the downlink control information, the terminal device can determine the reference precoding matrix from the predefined precoding matrix based on the index information of the reference precoding matrix included in the first information.

[0034] In another possible scenario of the first aspect, the predefined precoding matrix is ​​determined based on at least one of the following: the number of antenna ports of the terminal device, the coherence capability of the antenna ports, the maximum uplink transmission rank that the terminal device can support, and the maximum rank that the network device indicates the terminal device can use.

[0035] Optionally, the network device can determine candidate precoding matrices based on the number of antenna ports of the terminal device, and then determine a predefined precoding matrix from the candidate precoding matrices based on the coherence capability of the antenna ports. Other specific implementations are described in subsequent embodiments and will not be repeated here.

[0036] It should be understood that if the coherence capability of the antenna port of the terminal device is fully coherent, the predefined precoding matrix can be a fully phase interferometry coding matrix, a partially phase interferometry coding matrix, or a non-phase interferometry coding matrix. If the coherence capability of the antenna port of the terminal device is partially coherent, the predefined precoding matrix can be a partially phase interferometry coding matrix or a non-phase interferometry coding matrix. If the coherence capability of the antenna port of the terminal device is non-coherent, the predefined precoding matrix can only be a non-phase interferometry coding matrix.

[0037] In another possible scenario of the first aspect, the reference precoding matrix is ​​the precoding matrix corresponding to an uplink sub-band contained within the frequency domain of the uplink bandwidth portion; or, the reference precoding matrix is ​​the precoding matrix corresponding to an uplink sub-band contained within the frequency domain of the uplink data channel.

[0038] In this implementation, the reference precoding matrix indicated by the first information configured by the network device is either the precoding matrix corresponding to any uplink sub-band within the frequency domain of the uplink bandwidth portion, or the precoding matrix corresponding to an uplink sub-band contained within the frequency domain of the uplink data channel, making the reference precoding matrix more consistent with the channel characteristics.

[0039] Secondly, a communication method is provided, applied to a network device. The method includes: the network device sending downlink control information for scheduling a downlink data channel to a terminal device, and then receiving an uplink data channel sent by the terminal device. The uplink data channel contains transmission data from one or more transport layers, and includes multiple uplink sub-bands within its frequency domain. The downlink control information carries first information and second information. The first information is used to indicate a reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band among the multiple uplink sub-bands and the uplink sub-band corresponding to the reference precoding matrix within the same transport layer.

[0040] In this implementation, the downlink control information configured by the network device only includes first information and second information indicating the reference precoding matrix. The terminal device can determine the precoding matrix corresponding to each of the multiple uplink subbands based on the first information and the second information. Since the phase difference indicated by the second information is less than the number of uplink subbands included in the frequency domain of the uplink data channel, and the overhead required to indicate a phase difference is usually less than the overhead required to indicate a precoding matrix, the overhead required to indicate the downlink control information is reduced.

[0041] In one possible scenario of the second aspect, the second information is used to indicate the phase corresponding to each of the at least one transport layers.

[0042] In this implementation, the network device carries first information and second information in the downlink control information. After the terminal device receives the reference precoding matrix indicated by the first information and the phase indicated by the second information, it can determine the precoding matrix corresponding to the uplink subband. This eliminates the need for the downlink control information to indicate the precoding matrices corresponding to multiple uplink subbands separately, thereby reducing the overhead required for downlink control information indication.

[0043] In another possible scenario of the second aspect, the second information includes index information of the phase corresponding to each transport layer in at least one transport layer; or, the second information includes index information of the phase corresponding to the remaining transport layers in at least one transport layer, excluding the reference transport layer.

[0044] In this implementation, when the uplink data channel contains transmission data from multiple transmission layers, the second information may include the index information of the phase corresponding to each transmission layer. The terminal device can then determine the precoding matrix corresponding to different transmission layers of the uplink subband based on the reference precoding matrix and the phase corresponding to different transmission layers.

[0045] In another possible scenario of the second aspect, the second information includes index information of the phase corresponding to the reference transport layer and a first differential phase of at least one transport layer, the first differential phase being the difference between the phase corresponding to the transport layer and the phase corresponding to the reference transport layer.

[0046] In this implementation, since the overhead required for the second information to indicate the first differential phase is less than the overhead required for the second information to indicate the phase corresponding to the reference transport layer, the second information indicates the phase corresponding to the reference transport layer and the first differential phase corresponding to at least one of the multiple transport layers, thus reducing the resource overhead required for the second information.

[0047] In another possible scenario of the second aspect, the second information is used to indicate a vector corresponding to each of at least one transport layer; the vector corresponding to the transport layer includes multiple elements, the multiple elements correspond to multiple uplink subbands, and one element is used to indicate the phase difference between the uplink subband corresponding to the element and the uplink subband corresponding to the reference precoding matrix in the transport layer.

[0048] In another possible scenario of the second aspect, the second information includes a vector-related indication corresponding to each of the multiple transport layers; or, the second information includes a vector-related indication corresponding to each transport layer other than the reference transport layer.

[0049] In this implementation, when the uplink data channel contains transmission data from multiple transmission layers, the second information can indicate the vector-related indication for each transmission layer. The terminal device can then determine the precoding matrix corresponding to different transmission layers in the uplink subband based on the reference precoding matrix and the vectors corresponding to different transmission layers.

[0050] In another possible scenario of the second aspect, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

[0051] In this implementation, the number of transport layers included in the uplink data channel is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use. The number of phases or vectors indicated by the second information is determined based on the number of transport layers. Therefore, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

[0052] In another possible scenario of the second aspect, the downlink control information also carries third information, which is used to indicate the initial phase of the precoding matrix corresponding to the multiple uplink subbands.

[0053] In this implementation, since the initial phase of the precoding matrix corresponding to the uplink subband may be non-zero, the network device can be configured to carry third information in the downlink control information to indicate the initial phase of the precoding matrix corresponding to the uplink subband. By referring to the initial phase and the phase indicated by the first and second information, the accuracy of determining the precoding matrix corresponding to the uplink subband is improved.

[0054] In another possible scenario of the second aspect, the initial phase includes initial phases corresponding to multiple transport layers; the third information includes index information of the initial phase of each transport layer; or, the third information includes the initial phase of a reference transport layer and a second differential phase of at least one of the multiple transport layers, the second differential phase being the difference between the initial phase of the transport layer and the initial phase of the reference transport layer.

[0055] In this implementation, the network device carries third information in the downlink control information. After receiving the third information carried in the downlink control information, the terminal device can determine the initial phase of each transport layer based on the index information of the initial phase of each transport layer included in the third information. In this way, the terminal device can determine the precoding matrix corresponding to different transport layers in the uplink subband based on the initial phase of each transport layer.

[0056] Thirdly, a communication device is provided for use in a terminal device, the device comprising: a module for performing the method described in the first aspect and any possible implementation thereof.

[0057] Fourthly, a communication apparatus is provided for use in a network device, the apparatus comprising: a module for performing the method of the second aspect and any possible implementation thereof.

[0058] Fifthly, a communication system is provided, comprising: a communication device for performing the method of the first aspect and any possible implementation thereof, and a communication device for performing the method of the second aspect and any possible implementation thereof.

[0059] Sixthly, a communication device is provided, comprising: a transceiver, a processor, and a memory. The memory stores computer programs or instructions, and the processor controls the transceiver to transmit and receive signals. The processor also calls and executes the computer programs or instructions stored in the memory, causing the processor to implement any of the above aspects and any possible implementations of those aspects.

[0060] In a seventh aspect, a communication device is provided, comprising: a processor; the processor being configured to invoke a computer program or instructions in a memory, causing the communication device to execute any of the above aspects and any possible implementation thereof.

[0061] Optionally, the communication device further includes a memory for storing program instructions. The processor is coupled to the memory via an interface.

[0062] Eighthly, a chip device is provided, including a processor for invoking a computer program or instructions in the memory to cause the processor to perform any of the above aspects and any possible implementation thereof.

[0063] Alternatively, the processor may be coupled to the memory via an interface.

[0064] Ninthly, a chip system is provided, including a memory and a processor, wherein a program / instruction stored in the memory, when executed by the processor, implements any of the above aspects and any possible implementation of the above aspects.

[0065] In a tenth aspect, a computer-readable storage medium is provided, on which a computer program / instructions are stored, which, when executed by a processor, implement any of the above aspects and any possible implementation of the above aspects.

[0066] Eleventhly, a computer program product is provided, including a computer program / instruction that, when executed by a processor, implements any of the above aspects and any possible implementation of the above aspects. Attached Figure Description

[0067] Figure 1 An example diagram illustrating the frequency domain range of an uplink data channel provided in an embodiment of this application;

[0068] Figure 2 An example diagram illustrating an uplink subband partitioning method provided in an embodiment of this application;

[0069] Figure 3 A schematic diagram of a communication system provided in an embodiment of this application;

[0070] Figure 4 A flowchart illustrating a communication method provided in an embodiment of this application;

[0071] Figure 5 An example diagram of a precoding matrix corresponding to an uplink subband provided in this application embodiment;

[0072] Figure 6 An example diagram of a precoding matrix corresponding to another uplink subband provided in this application embodiment;

[0073] Figure 7 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0074] Figure 8 This is a schematic diagram of the hardware structure of a communication device provided in an embodiment of this application;

[0075] Figure 9 This is a schematic diagram of the structure of a communication system provided in an embodiment of this application. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the term "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 existing alone, A and B existing simultaneously, and B existing alone.

[0077] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0078] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0079] First, to facilitate understanding of the methods provided in this application, the technical terms involved in this application will be explained.

[0080] 1. Uplink and downlink: These refer to the direction of signal or data transmission. Uplink refers to the transmission direction from the terminal device to the network side, and downlink refers to the transmission direction from the network side to the terminal device. Data transmitted uplink can be called uplink data, and data transmitted downlink can be called downlink data.

[0081] 2. Physical Resource Block (PRB): A PRB is a resource unit used for data transmission in a wireless communication system. A PRB consists of several consecutive subcarriers in the frequency domain and spans one or more symbols in the time domain.

[0082] 3. Frequency domain bandwidth: refers to the bandwidth of the transmission resources used to transmit data in the frequency domain, that is, the frequency range occupied by the data, usually expressed in Hertz (Hz).

[0083] When scheduling uplink data transmission for terminal devices, the network side typically indicates the frequency domain range of the uplink data transmission channel in the downlink control information (DCI). This frequency domain range can be replaced by a description of the frequency domain bandwidth. For example, Figure 1 The frequency domain range of the physical uplink shared channel (PUSCH) within the shaded area is shown, as follows: Figure 1 As shown, the frequency domain range of the uplink data channel is usually within the uplink bandwidth part (BWP).

[0084] Furthermore, the size of the frequency domain bandwidth determines how many PRBs can be allocated. The wider the bandwidth, the more PRBs can be allocated, thus providing a higher data transmission rate. A PRB is a unit of frequency domain bandwidth division; that is, the frequency domain bandwidth is divided into multiple PRBs, and each PRB can be independently allocated to a user for data transmission.

[0085] 4. Subband: A subband refers to a narrow frequency band divided from a wide frequency domain bandwidth. A single frequency domain bandwidth can be divided into multiple subbands, and a subband can include one or more subcarriers. Different subbands correspond to different frequency domain ranges. Based on the data transmission direction, subbands also include uplink subbands and downlink subbands. The uplink subband refers to the portion of the frequency domain from which the terminal device transmits uplink data to the network side. The downlink subband refers to the portion of the frequency domain from which the network side transmits downlink data to the terminal device.

[0086] Terminal devices can determine the uplink subband based on the frequency domain range of the uplink data channel and the uplink subband size. Alternatively, terminal devices can also determine the uplink subband based on the frequency domain range of the uplink bandwidth portion and the uplink subband size. The uplink subband size can be predefined (e.g., determined based on the uplink transmission bandwidth) or configured by the network side. The uplink subband size refers to the number of PRBs included in an uplink subband.

[0087] In one scenario, the frequency domain range of the uplink data channel, or the frequency domain range of the uplink bandwidth portion, includes multiple uplink sub-bands, each containing the same number of PRBs. For example... Figure 2 As shown in (a), the uplink bandwidth portion contains N uplink sub-bands in the frequency domain, and each uplink sub-band contains 4 PRBs.

[0088] In another scenario, the frequency domain range of the uplink data channel or the frequency domain range of the uplink bandwidth portion may contain multiple uplink subbands, and the number of PRBs contained in different uplink subbands may differ. The number of PRBs contained in the first uplink subband and / or the last uplink subband may differ from the number of PRBs contained in other uplink subbands.

[0089] The number of PRBs contained in the first uplink subband and the number of PRBs contained in the last uplink subband can be determined as follows: The number of PRBs contained in the first uplink subband can be: N SB -(N start modN SB The number of PRBs contained in the last uplink subband can be: (N) start +N size )modN SB Among them, N SB Indicates the size of the uplink subband; N start Indicates the index of the starting physical resource block for the frequency domain range of the uplink bandwidth portion; N size This refers to the number of PRBs contained within the frequency domain range of the uplink bandwidth portion.

[0090] For example, such as Figure 2 As shown in (b), the uplink bandwidth contains N uplink sub-bands in the frequency domain. The first uplink sub-band contains 3 PRBs, the Nth uplink sub-band contains 1 PRB, and the remaining uplink sub-bands each contain 4 PRBs.

[0091] 5. Precoding: This refers to the process where, if the terminal device can obtain certain information about the channel (a prerequisite for precoding), it can use this information to preprocess uplink data to improve the system's transmission rate and link reliability. The technique of using the terminal device's channel state information (CSI) to preprocess uplink data is called precoding. It should be understood that because wireless channels typically exhibit multipath effects, frequency-selective fading, and time-varying characteristics, precoding can optimize data transmission, making the transmitted uplink data more suitable for channel characteristics, thereby improving data reception quality. In multiple-input multiple-output (MIMO) systems, precoding can be used to achieve spatial multiplexing, that is, simultaneously transmitting multiple data streams within the same uplink transmission frequency domain, thereby increasing the data transmission rate.

[0092] In one example, when the terminal device performs uplink transmission, it uses the same precoding matrix when precoding uplink data in multiple PRBs of an uplink subband.

[0093] 6. Antenna Port: In wireless communication systems, an antenna port is a logical concept used to describe the interface between the terminal device and the antenna during signal transmission or reception. One antenna port can correspond to one transmitting antenna or multiple transmitting antennas. Antenna ports can be distinguished by a reference signal (RS): if the terminal device transmits a reference signal through multiple antennas, then those multiple antennas correspond to the same antenna port. If two different reference signals are transmitted through the same antenna, then that antenna corresponds to two independent antenna ports.

[0094] The number of antenna ports on a terminal device is usually related to the maximum uplink rank supported by the terminal device. For example, a terminal device with 2x2 multiple-input multiple-output (MIMO) capability typically has two antenna ports.

[0095] 7. Uplink codebook: This refers to the set of different precoding matrices supported by the protocol based on the capabilities of the terminal device. For example, the protocol defines the codebook used by the terminal device with 2Tx transmit antenna ports (referred to as the 2Tx codebook) and the codebook used by the terminal device with 4Tx transmit antenna ports (referred to as the 4Tx codebook). Among them, the precoding matrices in the 4Tx codebook can support uplink transmission from layer 1 to layer 4 respectively.

[0096] If a terminal device can maintain the relative phase of different antenna ports (or RF links), multiple antenna ports can use different phases when transmitting the same modulation symbol, allowing the terminal to generate adaptive digital beams. The 4Tx codebook considers the coherence capability of the terminal device's antenna ports, which includes fully coherent, partially coherent, and non-coherent capabilities.

[0097] In this context, "fully coherent" means that all antenna ports of the terminal device can transmit coherently, meaning all antenna ports can maintain relative phase. The corresponding precoding matrix is ​​called a fully coherent interferometry (WCI) coding matrix, specifically characterized by non-zero elements in each column vector. "Partially coherent" means that some antenna ports of the terminal device can transmit coherently, meaning some antenna ports can maintain relative phase. The corresponding precoding matrix is ​​called a partially coherent interferometry (WCI) coding matrix, specifically characterized by non-zero elements in each column vector. "Incoherent" means that no two antenna ports of the terminal device can transmit coherently, meaning no two antenna ports can maintain relative phase. The corresponding precoding matrix is ​​called a non-interferometry (NIQ) coding matrix, specifically characterized by non-zero elements in each column vector.

[0098] If the antenna port of the terminal device is fully coherent, the precoding matrix used for precoding uplink data can be a fully phase interferometry (WCI) coding matrix, a partially phase interferometry (MPI) coding matrix, or a non-phase interferometry (NPI) coding matrix. If the antenna port of the terminal device is partially coherent, the precoding matrix used for precoding uplink data can be either a partially phase interferometry (MPI) coding matrix or a NPI coding matrix. If the antenna port of the terminal device is incoherent, the precoding matrix used for precoding uplink data can only be a NPI coding matrix.

[0099] For example, Table 1 below shows the precoding matrix W that a terminal device can use when supporting data transmission through one transport layer via four antenna ports. That is, when the layer number v=1, the precoding matrix used by the terminal device to encode uplink data when transmitting data through four antenna ports includes four elements corresponding to these four antenna ports. Different transmission precoding matrix indicator (TPMI) index information corresponds to different precoding matrices W. Among them, precoding matrices with TPMI index information of 0 to 3 are non-phase interferometry coding matrices, precoding matrices with TPMI index information of 4 to 11 are partial phase interferometry coding matrices, and precoding matrices with TPMI index information of 12 to 27 are full phase interferometry coding matrices.

[0100] Table 1

[0101]

[0102]

[0103] For example, Table 2 below shows the precoding matrix W used by the terminal device when supporting data transmission through two transport layers via four antenna ports. Specifically, when v=2, the precoding matrix used by the terminal device to encode uplink data via four antenna ports includes two column vectors, each corresponding to one of the two transport layers. Each transport layer's column vector contains four elements, each corresponding to one of the four antenna ports. Specifically, precoding matrices with TPMI index information of 0–5 are non-phase interferometry coding matrices, those with TPMI index information of 6–13 are partially phase interferometry coding matrices, and those with TPMI index information of 14–21 are fully phase interferometry coding matrices.

[0104] Table 2

[0105]

[0106]

[0107] For example, Table 3 below shows the precoding matrix W used by the terminal device when supporting data transmission through three transport layers via four antenna ports. Specifically, when v=3, the precoding matrix used by the terminal device to encode uplink data via four antenna ports includes three column vectors, each corresponding to one of the three transport layers. Each transport layer's column vector contains four elements, each corresponding to one of the four antenna ports. Specifically, the precoding matrix with a TPMI index of 0 is a non-phase interferometry coding matrix, the precoding matrix with TPMI indices of 1-2 is a partial phase interferometry coding matrix, and the precoding matrix with TPMI indices of 3-6 is a full phase interferometry coding matrix.

[0108] Table 3

[0109]

[0110] For example, Table 4 shows the precoding matrix W used by the terminal device when supporting data transmission through four transmission layers via four antenna ports. Specifically, when v=4, the precoding matrix used by the terminal device to encode uplink data transmitted through four antenna ports includes four column vectors, each corresponding to one of the four transmission layers. Each transmission layer's column vector contains four elements, each corresponding to one of the four antenna ports. Specifically, the precoding matrix with a TPMI index of 0 is a non-phase interferometry coding matrix, the precoding matrix with TPMI indices of 1-2 is a partial phase interferometry coding matrix, and the precoding matrix with TPMI indices of 3-4 is a full phase interferometry coding matrix.

[0111] Table 4

[0112]

[0113] In related technologies, terminal devices typically employ wideband precoding when precoding uplink data. This means that the terminal device uses the same precoding matrix when precoding uplink data to be transmitted across all frequency ranges of the uplink data channel. For example, with a terminal device having four antenna ports, based on the 4Tx precoding matrices used for uplink transmission shown in Tables 1 to 4 above, the network device can select an appropriate uplink transmission layer number based on the measured uplink channel information, choose a suitable precoding matrix from the codebook corresponding to that uplink transmission layer number, and then indicate the determined uplink transmission layer number and TPMI index information to the terminal device via downlink control information.

[0114] However, wideband precoding refers to the terminal device using the same precoding matrix to precode the uplink data to be transmitted across all frequency ranges of the uplink data channel. However, due to the multipath effect of the uplink data channel, the channel exhibits frequency selectivity, meaning that the channel response (e.g., phase shift) differs across uplink sub-bands in different frequency ranges, resulting in significant differences in channel conditions between different uplink sub-bands. In this case, using the same precoding matrix for all uplink sub-bands within the frequency range of the uplink data channel will lead to performance degradation in some uplink sub-bands.

[0115] When the uplink data channel includes multiple uplink subbands, and the precoding matrices corresponding to different uplink subbands are different, the network device needs to indicate the precoding matrix corresponding to each uplink subband to the terminal device through downlink control information. For example, the TPMI index information of the precoding matrix corresponding to each uplink subband can be carried in the downlink control information to indicate this to the terminal device. When there are a large number of uplink subbands, a large amount of TPMI index information needs to be carried in the downlink control information, which can lead to the downlink control information indicating a large amount of system resources being consumed, resulting in high resource overhead.

[0116] To reduce the resource overhead required for downlink control information indication, this application provides a communication method. The method includes: a network device sending downlink control information to a terminal device. The downlink control information is used to schedule an uplink data channel, which contains transmission data from one or more transport layers. The uplink data channel includes multiple uplink sub-bands within its frequency domain. The downlink control information carries first information and second information. The first information indicates a reference precoding matrix, and the second information determines the phase difference between any uplink sub-band and the uplink sub-band corresponding to the reference precoding matrix within the same transport layer. After receiving the downlink control information from the network device, the terminal device determines the precoding matrix corresponding to each uplink sub-band based on the reference precoding matrix and the second information. The terminal device precodes the uplink data transmitted by each uplink sub-band according to the precoding matrix corresponding to that uplink sub-band and then transmits the uplink data channel including multiple uplink sub-bands to the network device.

[0117] Therefore, network devices do not need to carry the TPMI index information of the precoding matrix corresponding to each uplink subband in the downlink control information to indicate to the terminal device. The terminal device can determine the precoding matrix corresponding to all uplink subbands based on the downlink control information using only the first and second information carried in the downlink control information, thereby reducing the resource overhead required for downlink control information indication.

[0118] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0119] For example, the communication method provided in this application embodiment can be applied to any of the following communication systems: Long Term Evolution (LTE) system, Global System for Mobile Communication (GSM), 5th Generation (5G) communication system, communication systems after 5G, New Radio Access Technology (NR) system, 5.5G system or 6G system, and future communication systems, etc. Of course, the communication system may also include Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, Terrestrial Radio Access Network system, and GSM EDGE Radio Access Network (GERAN) system.

[0120] Furthermore, the technical solution provided in this embodiment can also be applied to wireless communication systems involving multiple terminals, such as public land mobile network (PLMN) systems and vehicle-to-X (V2X) systems. V2X systems can include vehicle-to-network (V2N) systems, vehicle-to-vehicle (V2V) systems, vehicle-to-infrastructure (V2I) systems, vehicle-to-pedestrian (V2P) systems, long-term evolution-vehicle (LTE-V) systems, vehicle-to-everything (V2X) systems, machine-type communication (MTC) systems, Internet of Things (IoT) systems, long-term evolution-machine (LTE-M) systems, and machine-to-machine (M2M) systems, etc., without limitation.

[0121] For example, Figure 3This is a schematic diagram of a communication system provided in an embodiment of this application; wherein, the communication system 300 may include at least one network device, such as Figure 3 The network device 310 shown; the communication system 300 may also include at least one terminal device, such as Figure 3 The terminal device 320 is shown in the diagram. The network device 310 and the terminal device 320 can communicate via a wireless link. Communication devices in this communication system, for example, between the network device 310 and the terminal device 320, can communicate using multi-antenna technology.

[0122] It should be noted that, Figure 3 This is a simplified illustration for ease of understanding only. For example, the communication system may also include other devices, such as wireless relay devices and / or wireless backhaul devices. Figure 3 The figures are not shown. In practical applications, this communication system may include multiple network devices or multiple terminal devices. This application does not limit the number of network devices and terminal devices included in the communication system.

[0123] Figure 3 The terminal device 320 can be a device with wireless transceiver capabilities or a chip or chip system that can be installed on the device. It allows users to access the network and is a device used to provide voice and / or data connectivity to users. The terminal device can also be called a terminal device, user equipment (UE), user unit, terminal, mobile station (MS), or mobile terminal (MT), etc.

[0124] For example, the terminal device 320 may be a mobile phone, a tablet computer, or a computer with wireless transceiver capabilities. Terminal equipment can also be user stations, mobile stations, remote stations, remote terminal equipment, mobile terminal equipment, user terminal equipment, wireless communication equipment, user agents, user devices, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices, processing devices connected to wireless modems, in-vehicle equipment, wearable devices, terminal equipment in the Internet of Things (IoT), home appliances, virtual reality (VR) terminals, augmented reality (AR) terminals, wireless terminals in industrial control, wireless terminals in autonomous driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in smart cities, wireless terminals in smart homes, vehicles with vehicle-to-vehicle (V2V) communication capabilities, intelligent connected vehicles, and unmanned aerial vehicles (UAVs). Unrestricted access is allowed for drones with U2U (to-UAV, U2U) communication capabilities, terminal devices in future networks, terminal devices in future evolved public land mobile networks (PLMNs), Wi-Fi stations (STAs), or terminal nodes (T-nodes) in satellite navigation systems. It is understood that the terminal device and the mobile user can be completely independent. All user-related information can be stored in a subscriber identity module (SIM) card, which can be used on the terminal device. The terminal device can interact with network-side devices by transmitting and / or receiving signals over the air interface.

[0125] Figure 3The network device 310 can be any device deployed in the access network capable of wireless communication with terminal devices. It can also be a chip or chip system configurable within such a device, a logical node or module, or a function implemented in software. Its main responsibilities include air interface-side wireless physical control, resource scheduling, wireless resource management, quality of service management, data compression and encryption, wireless access control, and mobility management. Specifically, the network device can be either a wired access device or a wireless access device.

[0126] For example, a network device can consist of one or more access network (AN) / radio access network (RAN) nodes. AN / RAN nodes can be various types of base stations, such as: satellite base stations, evolved Node Bs (gNBs), transmission reception points (TRPs), evolved Node Bs (eNBs), radio network controllers (RNCs), Node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (e.g., home evolved Node Bs, or home Node Bs (HNBs), macro base stations, micro base stations, pico base stations, small cells, relay stations, balloon stations, drone stations, wireless backhaul nodes, baseband units (BBUs), or wireless fidelity (Wi-Fi) access points (APs), etc. It is understood that network devices can be terrestrial devices or non-terrestrial devices (such as satellites, drones, high-altitude communication equipment, etc.). Furthermore, in communication systems employing different wireless access technologies, the names of network devices with base station functions may differ, and this application does not impose any restrictions on this.

[0127] Optionally, the network device 310 in this application embodiment may include various forms of base stations, such as macro base stations, micro base stations (also known as small stations), relay stations, access points, etc., and this application embodiment does not specifically limit them. In this application embodiment, the device for implementing the function of the network device may be a network device or a device capable of supporting the network device to implement the function, such as a chip system (e.g., a chip, or a processing system composed of multiple chips) or a modem. The following describes the method provided in this application embodiment using the example of a network device as the device for implementing the function of the network device.

[0128] The base station can be an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G communication system, a base station in a next-generation 6G communication system, a base station in a future communication system, an access point (AP) in a WiFi system, a wireless controller, relay station, access point, vehicle-mounted equipment, wearable devices, or other network equipment in future evolved communication systems. Alternatively, the network equipment can also be a module or unit that performs some of the functions of a base station; for example, it can be a central unit (CU) or a distributed unit (DU). This application does not limit the specific technology or equipment form used in the network equipment.

[0129] The communication method provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0130] Figure 4 This is a flowchart illustrating a communication method provided in an embodiment of this application. Figure 4 As shown, the method may include the following steps:

[0131] S401, the network device sends downlink control information to the terminal device; correspondingly, the terminal device receives the downlink control information from the network device.

[0132] Optionally, the downlink control information is DCI, and the network device can carry the downlink control information in the physical downlink control channel (PDCCH) and send it to the terminal device.

[0133] In this application, downlink control information is used to schedule the uplink data channel. The uplink data channel refers to the channel used to transmit uplink data. In this application, the uplink data channel can be a PUSCH or other channels, and is not limited thereto. The phrase "downlink control information is used to schedule the uplink data channel" can be replaced with "downlink control information is used to schedule uplink data."

[0134] In this application, the uplink data channel includes transmission data from at least one transport layer; in other words, the uplink data channel can support transmission through at least one transport layer. The uplink data channel includes multiple uplink sub-bands within its frequency domain. The specific implementation for determining the number of uplink sub-bands within the frequency domain of the uplink data channel, as described in the aforementioned technical terminology, will not be repeated here.

[0135] In this application, the downlink control information may carry / include / indicate the number of transport layers, the transmission resources used for transmitting uplink data channels, the frequency domain range of uplink data channels, or the number of uplink subbands, etc., and may also indicate / include other information. For example, in a precoding scenario, the downlink control information may also be used to indicate the precoding matrix corresponding to the uplink subbands included in the uplink data channel.

[0136] One implementation method: The downlink control information carries the first information and the second information.

[0137] The first information is used to indicate the reference precoding matrix. The second information is used to determine the phase difference between any uplink subband and the uplink subband corresponding to the reference precoding matrix within the same transport layer.

[0138] Optionally, when the uplink data channel contains transmission data of v transport layers, the reference precoding matrix indicated by the first information can be: W0 = [w1 w2 ... w v ]. Among them, w v This represents the precoding matrix of the v-th transport layer.

[0139] Optionally, the reference precoding matrix can be a precoding matrix corresponding to an uplink sub-band within the frequency domain range of the uplink bandwidth. This corresponding uplink sub-band can be any one of all uplink sub-bands within the frequency domain range of the uplink bandwidth, or it can be the uplink sub-band with the lowest index within the frequency domain range of the uplink bandwidth, or it can be the uplink sub-band with the highest index within the frequency domain range of the uplink bandwidth; there is no limitation. For example, using the above... Figure 2 As shown in (a), the uplink subband corresponding to the reference precoding matrix can be Figure 2 The first uplink subband in (a), or Figure 2 The Nth uplink subband shown in (a).

[0140] In this application, the uplink bandwidth includes the uplink data channel. Optionally, the reference precoding matrix can also be the precoding matrix corresponding to an uplink sub-band included within the frequency domain of the uplink data channel. The uplink sub-band corresponding to the reference precoding matrix can be any one of all uplink sub-bands included within the frequency domain of the uplink data channel, or it can be the uplink sub-band with the lowest index within the frequency domain of the uplink data channel, or it can be the uplink sub-band with the highest index within the frequency domain of the uplink data channel; there is no limitation.

[0141] Alternatively, the reference precoding matrix can also be any precoding matrix among the predefined precoding matrices.

[0142] A predefined precoding matrix refers to the precoding matrix that a terminal device can use when transmitting data through an uplink data channel via an antenna port. A predefined precoding matrix may include one or more pre-defined precoding matrices, and these matrices can be pre-set, such as those shown in any of Tables 1-4 above. In this application, the predefined precoding matrix can also be described as a set of precoding matrices or other names, without limitation.

[0143] Specifically, the predefined precoding matrix can be determined by one or more of the following information: the number of antenna ports on the terminal device, the coherence capability of the antenna ports, the maximum uplink transmission rank that the terminal device can support, or the maximum rank that the network device indicates the terminal device can use. Several methods for determining the predefined precoding matrix are given below:

[0144] Example 1: Determine the predefined precoding matrix based on the number of antenna ports of the terminal device.

[0145] Optionally, the network device can determine the number of transport layers supported by the uplink data channel based on the number of antenna ports of the terminal device, and then determine the predefined precoding matrix based on the number of transport layers. Assuming each antenna port can support one independent transport layer for data transmission, and the terminal device has 4 antenna ports, the network device can determine that the uplink data channel supports 4 transport layers, and the predefined precoding matrix is ​​one of the 8 precoding matrices listed in Table 4 above. Of course, it is also possible that some antenna ports cannot support an independent transport layer for data transmission. In this case, the network device can determine that the number of transport layers supported by the uplink data channel is less than the number of antenna ports.

[0146] For example, assuming the terminal device has 4 antenna ports, the network device determines that there are L1 predefined precoding matrices. The network device can then indicate any one of these L1 predefined precoding matrices as a reference precoding matrix. Conversely, assuming the terminal device has 8 antenna ports, the network device determines that there are L2 predefined precoding matrices. The network device can then indicate any one of these L2 predefined precoding matrices as a reference precoding matrix.

[0147] Example 2: Determine the predefined precoding matrix based on the number of antenna ports of the terminal device and the coherence capability of the antenna ports.

[0148] Optionally, the network device can determine the number of transport layers supported by the uplink data channel based on the number of antenna ports of the terminal device, and then determine the candidate precoding matrix based on the number of transport layers. Then, the network device can determine a predefined precoding matrix from the candidate precoding matrices based on the coherence capability of the antenna ports.

[0149] For example, assuming the terminal device has 4 antenna ports, and the uplink data channel supports data transmission at one transport layer, if the coherence capability of the terminal device's 4 antenna ports is fully coherent, the network device can determine that the predefined precoding matrix includes: non-interference coding matrices with TPMI index information of 0-3 in Table 1 above, partially interference coding matrices with TPMI index information of 4-11, and fully interference coding matrices with TPMI index information of 12-27. If the coherence capability of the terminal device's 4 antenna ports is partially coherent, the network device can determine that the predefined precoding matrix includes: non-interference coding matrices with TPMI index information of 0-3 in Table 1 above and partially interference coding matrices with TPMI index information of 4-11. If the coherence capability of the terminal device's 4 antenna ports is non-coherent, the network device can determine that the predefined precoding matrix includes: non-interference coding matrices with TPMI index information of 0-3 in Table 1 above.

[0150] For another example, assuming the terminal device has 4 antenna ports, and the uplink data channel contains data transmitted from two transport layers, if the coherence capability of the terminal device's 4 antenna ports is fully coherent, the network device can determine that the predefined precoding matrix includes: non-interference coding matrices with TPMI index information of 0-5 in Table 2 above, partially interference coding matrices with TPMI index information of 6-13, and fully interference coding matrices with TPMI index information of 14-21. If the coherence capability of the terminal device's 4 antenna ports is partially coherent, the network device can determine that the predefined precoding matrix includes: non-interference coding matrices with TPMI index information of 0-5 in Table 2 above and partially interference coding matrices with TPMI index information of 6-13. If the coherence capability of the terminal device's 4 antenna ports is non-coherent, the network device can determine that the predefined precoding matrix includes non-interference coding matrices with TPMI index information of 0-5 in Table 2 above.

[0151] Similarly, if the terminal device has four antenna ports, and the uplink data channel contains data transmitted across three transport layers, the network device can determine the predefined precoding matrices corresponding to different coherence capabilities of the antenna ports from Table 3 above. If the uplink data channel supports data transmission across four transport layers, the network device can determine the predefined precoding matrices corresponding to different coherence capabilities of the antenna ports from Table 4 above.

[0152] It should be understood that when the number of antenna ports of the terminal device is other values, the network device determines the specific implementation process of the predefined precoding matrix based on the coherence capability of the antenna ports. For example, the above describes the process of determining the predefined precoding matrix when the number of antenna ports of the terminal device is 4. It will not be described in detail here.

[0153] Example 3: Determine the predefined precoding matrix based on the number of antenna ports of the terminal device and the maximum uplink rank that the terminal device can support.

[0154] The maximum uplink rank that the terminal device can support indicates the maximum number of transport layers that the terminal device can include when transmitting uplink data through the uplink data channel. For example, if the maximum uplink rank that the terminal device can support is 4, then the terminal device can include a maximum of 4 transport layers when transmitting uplink data through the uplink data channel.

[0155] Optionally, the network device can determine the number of transport layers supported by the uplink data channel based on the number of antenna ports of the terminal device. The network device can compare the number of transport layers supported by the uplink data channel with the maximum number of transport layers that the terminal device can support for uplink transmission to determine the actual number of transport layers that the uplink data channel can support. Furthermore, the network device can determine a predefined precoding matrix based on the actual number of transport layers that the uplink data channel can support.

[0156] For example, assuming the terminal device has 4 antenna ports and a maximum uplink rank of 2 that it can support, the network device determines the 22 precoding matrices in Table 2 as predefined precoding matrices. The network device can indicate one precoding matrix from these 22 predefined precoding matrices as a reference precoding matrix. Similarly, assuming the terminal device has 4 antenna ports and a maximum uplink rank of 4 that it can support, the network device determines the 5 precoding matrices in Table 4 as predefined precoding matrices. The network device can indicate one precoding matrix from these 5 predefined precoding matrices as a reference precoding matrix.

[0157] Furthermore, after determining the predefined precoding matrix based on the number of antenna ports of the terminal device and the maximum uplink transmission rank that the terminal device can support, the network device can further filter the predefined precoding matrix based on the coherence capability of the antenna ports of the terminal device. For details, please refer to the process described above for determining the predefined precoding matrix based on the coherence capability of the antenna ports, which will not be repeated here.

[0158] Example 4: Determine the predefined precoding matrix based on the number of antenna ports of the terminal device and the maximum rank that the network device indicates the terminal device can use.

[0159] The maximum rank that the network device indicates the terminal device can use refers to the maximum uplink transmission rank that the network device is configured to support for the terminal device, i.e., the number of transport layers that the uplink data channel can actually support for data transmission. The maximum rank that the network device indicates the terminal device can use is less than or equal to the maximum uplink transmission rank that the terminal device can support.

[0160] Optionally, the network device can determine the number of transport layers supported by the uplink data channel based on the number of antenna ports of the terminal device. The network device can compare the number of transport layers supported by the uplink data channel with the maximum rank that the terminal device can use as indicated by the network device to determine the actual number of transport layers that the uplink data channel can support. Furthermore, the network device can determine a predefined precoding matrix based on the actual number of transport layers that the uplink data channel can support. After determining the predefined precoding matrix, the network device can select one precoding matrix from the predefined precoding matrices as a reference precoding matrix.

[0161] For example, suppose the terminal device has 4 antenna ports, the maximum uplink rank it can support is 2, and the network device indicates that the maximum rank it can use is 1. In this case, the network device determines the 28 precoding matrices in Table 1 as predefined precoding matrices. The network device can indicate one precoding matrix from these 28 predefined precoding matrices as a reference precoding matrix. Assuming the terminal device has 4 antenna ports, the maximum uplink rank it can support is 4, and the network device indicates that the maximum rank it can use is 3, the network device determines the 8 precoding matrices in Table 3 as predefined precoding matrices. The network device can indicate one precoding matrix from these 8 predefined precoding matrices as a reference precoding matrix.

[0162] Furthermore, after determining the predefined precoding matrix based on the number of antenna ports of the terminal device and the maximum rank that the terminal device can use as indicated by the network device, the network device can further filter the predefined precoding matrix based on the coherence capability of the antenna ports of the terminal device. For details, please refer to the above process of the network device determining the precoding matrix for precoding uplink data by the terminal device based on the coherence capability of the antenna ports, which will not be repeated here.

[0163] In this embodiment, the first information may include index information of a reference precoding matrix. For example, after the network device selects a precoding matrix from predefined precoding matrices as a reference precoding matrix, the network device may configure the first information carried in the downlink control information to include the index information of the reference precoding matrix, so as to indicate the reference precoding matrix through the index information. Since the overhead required to indicate the index information of a reference precoding matrix is ​​small, and the second information does not directly include the precoding matrix but is used to indicate the phase difference, compared to directly indicating multiple precoding matrices in the downlink control information, the terminal device can determine the precoding matrices corresponding to all uplink subbands by only including the index information in the first information carried in the downlink control information to indicate the reference precoding matrix and the second information, thus reducing the overhead required for downlink control information indication.

[0164] For example, assuming the network device determines that the reference precoding matrix is ​​the precoding matrix with TPMI index information of 0 in Table 1 above, the first information may include TPMI index information 0. Thus, after receiving downlink control information from the network device, the terminal device can determine the reference precoding matrix based on the index information of the precoding matrix included in the first information carried by the downlink control information.

[0165] S402, the terminal device transmits an uplink data channel to the network device. Correspondingly, the network device receives the uplink data channel from the terminal device.

[0166] In this embodiment, after receiving downlink control information from the network device, the terminal device determines the precoding matrix used by all uplink subbands based on the reference precoding matrix indicated by the first information and the second information carried in the downlink control information. Thus, the downlink control information configured by the network device includes the first and second information. The terminal device can determine the precoding matrix used by all uplink subbands based on the first and second information. Since the second information only needs to indicate the phase difference between the transport layer in the uplink subband and the same transport layer in the uplink subband corresponding to the reference precoding matrix, the overhead of downlink control information indication is reduced compared to the network device indicating the precoding matrices corresponding to multiple uplink subbands separately through multiple downlink control information.

[0167] The process by which the terminal device determines the precoding matrix corresponding to multiple uplink subbands based on the reference precoding matrix indicated by the first information and the second information can be referred to the following, and will not be repeated here.

[0168] In this embodiment, when a terminal device sends uplink data to a network device through multiple uplink sub-bands within the frequency domain of the uplink data channel, the terminal device uses a precoding matrix corresponding to each uplink sub-band to precode the uplink data transmitted in that uplink sub-band. Compared to using the same precoding matrix for precoding multiple uplink sub-bands of the uplink data channel, this improves data transmission quality and system performance.

[0169] In summary, in the communication method of this application embodiment, after the network device sends downlink control information to the terminal device, the terminal device can determine the reference precoding matrix indicated by the first information carried in the downlink control information and the precoding matrices corresponding to multiple uplink subbands based on the second information. It is evident that the network device does not need to send multiple downlink control messages to the terminal device to indicate the precoding matrices corresponding to multiple uplink subbands, saving the resource overhead required for downlink control information. Furthermore, compared to the prior art where the terminal device uses wideband precoding to precode uplink data in the uplink data channel, in this application embodiment, the terminal device uses corresponding precoding matrices to encode the uplink data in multiple uplink subbands of the uplink data channel. This allows for optimization of the channel characteristics of each uplink subband, more effective utilization of spectrum resources, and thus improved data transmission efficiency.

[0170] The following is about Figure 4 The process by which the terminal device determines the precoding matrix corresponding to multiple uplink subbands in the method shown is introduced.

[0171] Method 1: The second information is used to indicate the phase corresponding to each transport layer in at least one transport layer.

[0172] One phase corresponds to one transport layer. For example, in the case of one transport layer, the second information indicates one phase; in the case of multiple transport layers, the second information indicates multiple phases.

[0173] In this embodiment of the application, the phase corresponding to the transport layer can be used to determine the phase difference between the first uplink subband and the uplink subband corresponding to the reference precoding matrix in the same transport layer. The first uplink subband can be any uplink subband included in the uplink data channel.

[0174] For example, the phase indicated by the second information can be used to determine the phase difference between the first transport layer of the first uplink subband and the first transport layer in the uplink subband corresponding to the reference precoding matrix.

[0175] In this embodiment, the terminal device can determine the phase difference between any uplink sub-band among multiple uplink sub-bands and the uplink sub-band corresponding to the reference precoding matrix at the same transport layer based on the second information. For any uplink sub-band, the terminal device can determine the precoding matrix of the uplink sub-band based on the phase difference between the reference precoding matrix and the uplink sub-band. Optionally, the terminal device can determine the first coefficient based on the phase indicated by the second information and the index information of the first uplink sub-band. Furthermore, the terminal device determines the precoding matrix of the first uplink sub-band based on the reference precoding matrix and the first coefficient.

[0176] When the uplink data channel contains transmission data for one transport layer, the second information indicates the phase corresponding to that transport layer. This phase is the phase difference between the transport layer in any of the multiple uplink subbands and the transport layer in the uplink subband corresponding to the reference precoding matrix. In this case, the second information may include index information of the phase corresponding to that transport layer. After receiving the second information carried in the downlink control information, the terminal device can determine the phase corresponding to that transport layer based on the phase index information.

[0177] When the uplink data channel contains transmission data from multiple transport layers, the second information indicates the phases corresponding to multiple transport layers, with one phase corresponding to one transport layer. The phase corresponding to each transport layer is the phase difference between that transport layer in the first uplink sub-band and the same transport layer in the uplink sub-band corresponding to the reference precoding matrix. For example, the first phase could be the phase difference between the first transport layer in the first uplink sub-band and the first transport layer in the uplink sub-band corresponding to the reference precoding matrix. Therefore, the terminal device can subsequently determine the precoding matrices corresponding to different transport layers in the first uplink sub-band based on the reference precoding matrix and the phases corresponding to different transport layers.

[0178] When the second information indicates multiple phases, the second information may include index information of the phase corresponding to each transport layer in at least one transport layer. Thus, after receiving the second information carried in the downlink control information, the terminal device can directly determine the phase corresponding to each transport layer based on the index information of the phase corresponding to each transport layer included in the second information.

[0179] When the second information indicates phases corresponding to multiple transport layers, the second information includes index information of the phases corresponding to at least one transport layer other than the reference transport layer. The reference transport layer can be any of the multiple transport layers. For example, if the uplink data channel contains data transmitted through four transport layers, and the reference transport layer is the first transport layer, the second information may not include the index information of the phases corresponding to the first transport layer, but only include the index information of the phases corresponding to the second to fourth transport layers; that is, the second information may only include the index information of three phases. It should be understood that the phase of the reference transport layer can be a default phase (e.g., 0 or 2π), and the network device does not need to indicate the index information of the reference transport layer's phase through downlink control information, thus saving the indication overhead of downlink control information.

[0180] Optionally, when the second information indicates phases corresponding to multiple transport layers, the network device may be configured to carry one piece of second information in the downlink control information, which includes index information of the phases corresponding to multiple transport layers. Alternatively, the network device may also be configured to carry multiple pieces of second information in the downlink control information, each piece of second information including index information of a phase corresponding to a transport layer.

[0181] The phase corresponding to each transport layer in the at least one transport layer indicated by the second information mentioned above can be any phase from the predefined phases. In the embodiments of this application, the specific value of the phase is not limited. The predefined phase can also be called a phase set or other names, and is not limited.

[0182] For example, suppose there are K predefined phases. Alternatively, having K predefined phases can also be... Alternatively, there are K+1 predefined phases. The value of K can be configured by the network device, determined by the network device based on the capabilities of the terminal device, or predefined; no restrictions are imposed here.

[0183] When the second information indicates a phase corresponding to a transport layer, the phase indicated by the second information can be one indicated by the network device from the aforementioned K predefined phases, or one indicated by the aforementioned K=1 predefined phases. When the second information indicates phases corresponding to multiple transport layers, the multiple phases can be multiple different phases indicated by the network device from the aforementioned K predefined phases, or multiple different phases indicated by the aforementioned K=1 predefined phases.

[0184] It should be noted that the maximum value θ in the predefined phase mentioned above max It can be a predefined value (e.g., θ) maxIt can be π or 2π, etc., or a value configured for the network device; there are no restrictions here. In some cases, the maximum value θ in the predefined phase... max The value of θ is related to the delay spread of the uplink data channel; therefore, the maximum value θ in the predefined phase is configured by the network device. max This can improve the accuracy of the phase indicated by the second information.

[0185] Assuming the phase corresponding to the transport layer indicated by the second information is determined from the aforementioned K or K+1 predefined phases, then the number of bits occupied when the second information indicates a phase corresponding to a transport layer is: or The number of bits occupied when the second information indicates the phases corresponding to multiple transport layers is: or Wherein, maxRank is the number of phases indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use.

[0186] When the second information indicates phases corresponding to multiple transport layers, and the second information includes index information of the phases corresponding to the remaining transport layers (excluding the reference transport layer) within at least one transport layer, then the second information does not contain a phase indication of the reference transport layer. Assuming the phase corresponding to the transport layer indicated by the second information is determined from the aforementioned K or K+1 predefined phases, then the number of bits occupied when the second information indicates a phase corresponding to one transport layer is... or The number of bits occupied when the second information indicates the phases corresponding to multiple transport layers is: or Wherein, maxRank is the number of phases indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use.

[0187] In this application, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use. This can be understood as the maximum number of transport layers that the uplink data channel may include being determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use. The number of phases indicated by the second information corresponds to the maximum number of transport layers; therefore, the number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

[0188] For example, assuming that the maximum rank supported by the terminal device for uplink transmission is 4, the second information may indicate phases corresponding to at most 4 transmission layers. The number of bits occupied by the second information is the total number of bits occupied for indicating 4 phases. In this case, if the number of transmission layers of the uplink data channel scheduled by downlink control information is less than 4, for example, the number of transmission layers of the uplink data channel scheduled by downlink control information is 3, one of the phase indications indicated by the second information in the downlink control information is not used for determining the subband precoding. If the network device indicates that the maximum rank that the terminal device can use is 3, the second information indicates phases corresponding to 3 transmission layers. The number of bits occupied by the second information is the total number of bits occupied for indicating 3 phases. It is further assumed that the maximum rank supported by the terminal device for uplink transmission is 4, and the network device indicates that the maximum rank that the terminal device can use is 3. In this case, the second information indicates 3 phases. The number of bits occupied by the second information is the total number of bits occupied for indicating the phases corresponding to the 3 transmission layers.

[0189] In the case where the second information indicates phases corresponding to multiple transmission layers, in order to reduce the indication overhead of the second information, the second information may include index information of the phase corresponding to the reference transmission layer and a first differential phase of at least one transmission layer. The first differential phase is a difference value between the phase corresponding to the transmission layer and the phase corresponding to the reference transmission layer. It should be understood that since the first differential phase does not need to be selected from all predefined phases, indicating the first differential phase corresponding to at least one transmission layer in the multiple transmission layers through the second information can achieve the purpose of reducing the indication overhead of the second information.

[0190] For example, assuming that the reference transmission layer is the first transmission layer, the phase determined by the index information of the phase corresponding to the reference transmission layer included in the second information is θ1, and the first differential phase corresponding to the Q-th (Q>1) transmission layer is Δθ Q , the phase corresponding to the Q-th transmission layer may be θ1+Δθ Q , or θ1-Δθ Q . Assuming that the phase θ1 corresponding to the first transmission layer is selected from the K predefined phases described above, the number of bits occupied when the second information indicates the phase θ1 is Assuming that the first differential phase Δθ Q is selected from K d (where K d <K) predefined phases, the number of bits occupied when the second information includes the first differential phase is It can be seen that the overhead required for the second information to include the first differential phase is less than the overhead required for the second information to include the phases corresponding to the transmission layers.

[0191] Assuming that the phase corresponding to the reference transmission layer indicated by the second information is determined from K predefined phases, and the first differential phase is determined from K dIf determined from a predefined phase, then the number of bits occupied when the second information indicates the phase corresponding to multiple transport layers is... Wherein, maxRank is the number of phases indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use.

[0192] In this embodiment, after receiving the second information carried in the downlink control information, the terminal device can determine the first coefficient corresponding to the uplink subband based on the phase corresponding to the transport layer and the index information of the uplink subband. For example, assuming the phase indicated by the second information is θ0, the terminal device determines the first coefficient based on the phase and the index information of the uplink subband as follows: N represents the number of uplink subbands, and n represents the index information of the uplink subbands. The value of n can be 0, 1, 2, ..., N-1.

[0193] When the phase indicated by the second information corresponds to the phase of each of multiple transport layers, for example, the first phase could be the phase difference between the first transport layer in the uplink subband and the first transport layer in the uplink subband corresponding to the reference precoding matrix. The terminal device can determine the first coefficient based on the multiple phases and the uplink subband index information. For example, assuming the uplink data channel contains transmission data of v transport layers, and the second information indicates v phases, the first coefficients determined by the terminal device based on the v phases and the uplink subband index information are respectively...

[0194] Optionally, after the terminal device determines the first coefficient based on the phase indicated by the second information and the index information of the uplink subband, the terminal device can determine the precoding matrix corresponding to the uplink subband based on the product of the reference precoding matrix and the first coefficient.

[0195] For example, suppose the uplink data channel contains transmission data of v transport layers, and the second information indicates v phases, namely θ0, θ1, ..., θ2. v The reference precoding matrix is ​​W0 = [w1 w2 ... w v The terminal device can use the following formula to determine the precoding matrix corresponding to the (n+1)th uplink subband:

[0196]

[0197] In the above formula, W n W0 represents the precoding matrix corresponding to the (n+1)th uplink subband, N represents the number of uplink subbands contained in the frequency domain of the uplink data channel, and n represents the index information of the uplink subband, which can take the values ​​0, 1, 2, ..., N-1. This represents a diagonal matrix consisting of the first coefficient.

[0198] It should be understood that the terminal device can determine the precoding matrix corresponding to the N uplink subbands contained in the frequency domain of the uplink data channel according to the above formula (1) and different values ​​of n. When the value of N in the above formula (1) is the number of uplink subbands contained in the frequency domain of the uplink data channel, and the reference precoding matrix can be the precoding matrix corresponding to any uplink subband in the frequency domain of the uplink data channel.

[0199] For example, suppose the uplink data channel contains N uplink sub-bands in the frequency domain. The reference precoding matrix is ​​the precoding matrix corresponding to the uplink sub-band with the smallest index information in the frequency domain of the uplink data channel. That is, the reference precoding matrix is ​​the precoding matrix of the uplink sub-band with index information of 0. The reference precoding matrix is ​​W0 = [w1 w2 ... w v ].like Figure 5 As shown, the phase difference between the transmission layer of layer v in the uplink transmission subband indicated by the second information and the transmission layer of layer v in the uplink subband corresponding to the reference precoding matrix is... According to the above formula (1), the terminal device can determine the (n+1)th sub-band (i.e., index information is n) in the frequency domain range of the uplink data channel, and the precoding matrix used by the vth transport layer is as follows: For example, the precoding matrix used by the second subband (i.e., the index information is 1) and the v-th transport layer is... The precoding matrix used by the Nth subband (i.e., index information is N-1) and the vth transport layer is:

[0200] In summary, after receiving downlink control information, the terminal device can determine the precoding matrix corresponding to the uplink subband based on the reference precoding matrix indicated by the first information and the phase corresponding to each transport layer in at least one transport layer indicated by the second information. Therefore, the network device does not need to indicate the precoding matrix corresponding to each uplink subband through the downlink control information; it can determine the precoding matrix corresponding to the uplink subband solely based on the reference precoding matrix indicated by the first information and the phase indicated by the second information, thereby reducing the resource overhead required for downlink control information indication.

[0201] Method 2: The second information is used to indicate the vector corresponding to each transport layer in at least one transport layer.

[0202] At least one vector corresponds to one transport layer. For example, if there is one transport layer, the second information indicates one vector; if there are multiple transport layers, the second information indicates multiple vectors.

[0203] In this embodiment, the vector corresponding to the transport layer may include multiple elements, each corresponding to multiple uplink subbands. One element indicates the phase difference between the uplink subband corresponding to the element and the uplink subband corresponding to the reference precoding matrix in the transport layer. For example, the vector indicated by the second information can be used to determine the phase difference between the first uplink subband and the uplink subband corresponding to the reference precoding matrix in the first transport layer.

[0204] In this embodiment, after receiving the vector corresponding to the transport layer indicated by the second information, the terminal device can determine the second coefficient based on the vector corresponding to the transport layer and the index information of the first uplink sub-band. Then, the terminal device determines the precoding matrix of the first uplink sub-band based on the reference precoding matrix and the second coefficient.

[0205] In the case where the uplink data channel contains transmission data of a transport layer, the second information indicates a vector corresponding to the transport layer, which is the phase difference between the transport layer in the first uplink subband and the transport layer in the uplink subband corresponding to the reference precoding matrix.

[0206] When the uplink data channel contains transmission data across multiple transport layers, the second information indicates multiple vectors, each corresponding to one transport layer. The vector corresponding to each transport layer is used to determine the phase difference between the transport layer in the first uplink sub-band and the same transport layer in the uplink sub-band corresponding to the reference precoding matrix. For example, the first vector can be used to determine the phase difference between the first transport layer in the first uplink sub-band and the first transport layer in the uplink sub-band corresponding to the reference precoding matrix.

[0207] In cases where the second information indicates multiple vectors, the second information may include a vector-related indication for each of the multiple transport layers.

[0208] When the second information indicates multiple vectors, it may further include vector-related indications for each transport layer other than the reference transport layer. The reference transport layer can be any of the multiple transport layers. For example, if the uplink data channel contains data transmitted across four transport layers, with the first transport layer as the reference layer, the second information may not include the vector-related indications for the first transport layer, but only indicate the vector-related indications for the second to fourth transport layers. That is, the second information may only indicate three vector-related indications, thus reducing the indication overhead of the second information. It should be understood that the phase corresponding to the reference transport layer can be a default phase (e.g., 0 or 2π), and the network device does not need to indicate the corresponding vector-related indications for the reference transport layer through downlink control information, thereby saving the indication overhead of downlink control information.

[0209] Optionally, when the network device determines that the uplink data channel transmitted by the terminal device contains data transmitted through multiple transport layers, the downlink control information may carry a second piece of information to determine the phase difference between the multiple transport layers and the uplink sub-bands corresponding to the reference precoding within the same transport layer, based on multiple vectors indicated by the second piece of information. That is, the second piece of information includes multiple vectors, each used to determine the phase difference between a transport layer in the uplink sub-band and the uplink sub-band corresponding to the reference precoding within the same transport layer. Alternatively, the downlink control information may also carry multiple pieces of second information to determine the phase difference between each transport layer and the uplink sub-band corresponding to the reference precoding within the same transport layer, based on the vector indicated by each piece of second information. That is, each piece of second information includes a vector, which is used to determine the phase difference between the phase of a transport layer in the uplink sub-band and the uplink sub-band corresponding to the reference precoding within the same transport layer. In this embodiment, the method by which the network device configures the second information to indicate multiple vectors is not limited.

[0210] The vector corresponding to each of the above transport layers can be one of the predefined vector sets. In this embodiment, the specific value of the vector is not limited.

[0211] For example, a predefined set of vectors can be a discrete Fourier transform (DFT) vector, and the DFT vector can be... l∈{0,1,...,O·N-1}, where O is the oversampling factor, which can be a predefined value (e.g., O is 1 or 4), a value configured by the network device, or it can be non-existent (e.g., the default is 1); N is the number of uplink subbands; l is the vector-related indicator for each transport layer included in the second information, and the value of l is related to O and N.

[0212] Assume the number of bits used when the second information indicates a vector is . The number of bits occupied when the second information indicates multiple vectors is Here, maxRank is the number of vectors indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use. See the description above for details, which will not be repeated here.

[0213] When the second information indicates multiple vectors, it may further include vector-related indications for each transport layer other than the reference transport layer. In this case, the second information does not include vector-related indications for the reference transport layer. Assume the number of bits used when the second information indicates a single vector is... The number of bits occupied when the second information indicates multiple vectors is Here, maxRank is the number of vectors indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use. See the description above for details, which will not be repeated here.

[0214] In this embodiment, after receiving the second information carried in the downlink control information, the terminal device can determine the second coefficient corresponding to the uplink subband based on the vector indicated by the second information and the index information of the uplink subband. For example, assuming the vector indicated by the second information is l1, the terminal device determines the second coefficient based on the vector and the index information of the uplink subband as l1. N represents the number of uplink subbands contained in the frequency domain of the uplink data channel, and n represents the index information of the uplink subband. The value of n can be 0, 1, 2, ..., N-1.

[0215] When the second information indicates vectors corresponding to multiple transport layers, the terminal device can determine the second coefficient based on the phase difference indicated by the multiple vectors and the uplink subband index information. For example, assuming the uplink data channel contains transmission data from v transport layers, and the second information indicates v vectors, the second coefficient determined by the terminal device based on the v vectors and the uplink subband index information is:

[0216] Optionally, after determining the second coefficient based on the vector indicated by the second information and the index information of the first uplink sub-band, the terminal device can determine the precoding matrix corresponding to the first uplink sub-band based on the product of the reference precoding matrix and the second coefficient. For a detailed implementation process, please refer to the above-described implementation process of the terminal device determining the precoding matrix corresponding to the uplink sub-band based on the reference precoding matrix and the first coefficient; it will not be described in detail here.

[0217] For example, suppose the uplink data channel contains N uplink sub-bands in the frequency domain. The reference precoding matrix is ​​the precoding matrix corresponding to the uplink sub-band with the smallest index information in the frequency domain of the uplink data channel. That is, the reference precoding matrix is ​​the precoding matrix of the uplink sub-band with index information of 0. The reference precoding matrix is ​​W0 = [w1 w2 ... w v ].like Figure 6 As shown, the terminal device can determine the (n+1)th uplink sub-band (i.e., index information n) and the precoding matrix used by the v-th transport layer within the frequency domain range of the uplink data channel based on the product of the reference precoding matrix and the second coefficient. The phase difference between the v-th transport layer in the uplink transport subband indicated by the second information and the v-th transport layer in the uplink subband corresponding to the reference precoding matrix is... For example, the second uplink subband (i.e., index information is 1), and the precoding matrix used by the v-th transport layer are... The Nth uplink subband (i.e., index information is N-1), and the precoding matrix used by the vth transport layer are:

[0218] In summary, after receiving downlink control information, the terminal device can determine the precoding matrix corresponding to the uplink sub-band based on the reference precoding matrix indicated by the first information and the vector corresponding to at least one transport layer indicated by the second information. Therefore, the network device does not need to indicate the precoding matrix corresponding to each uplink sub-band through the downlink control information; it can determine the precoding matrix corresponding to all uplink sub-bands within the frequency domain of the uplink data channel using only the reference precoding matrix indicated by the first information and the vector indicated by the second information, thereby reducing the resource overhead required for downlink control information indication.

[0219] Another implementation method: the downlink control information carries the first information, the second information, and the third information.

[0220] The third piece of information is used to indicate the initial phase of the precoding matrix corresponding to the uplink subband within the frequency domain range of the uplink data channel.

[0221] It should be understood that in the above embodiments, when the terminal device determines the precoding matrix corresponding to all uplink subbands based on the reference precoding matrix and the second information, it does not consider the initial phase of the precoding matrix corresponding to all uplink subbands; that is, the initial phase of the precoding matrix corresponding to all uplink subbands is 0. In actual scenarios, the initial phase of the precoding matrix corresponding to the uplink subbands may not be 0. In this case, the network device indicates the initial phase of the precoding matrix corresponding to all uplink subbands through the third information. After the terminal device receives the first information, the second information, and the third information, the terminal device can determine the precoding matrix corresponding to all uplink subbands based on the reference precoding matrix indicated by the first information, the phase difference determined by the second information, and the initial phase indicated by the third information.

[0222] At least one initial phase corresponds to one transport layer. For example, in the case of one transport layer, the third information indicates one initial phase; in the case of multiple transport layers, the third information indicates multiple initial phases.

[0223] In the case where the uplink data channel contains transmission data of a transport layer, the third information indicates an initial phase that corresponds to the transport layer.

[0224] When the uplink data channel contains transmission data from multiple transport layers, the third information indicates multiple initial phases, each corresponding to one transport layer. Optionally, the third information may include index information of the initial phases. After receiving the third information, the terminal device determines the initial phase of each transport layer from a predefined pool of initial phases based on the index information of the initial phase of each transport layer. Then, based on the second information, it determines the phase difference between any uplink sub-band and the uplink sub-band corresponding to the reference precoding matrix within the same transport layer. For any uplink sub-band, the terminal device determines the final phase corresponding to the uplink sub-band based on the initial phase and the phase difference. Finally, the terminal device determines the precoding matrix of the uplink sub-band based on the product of the reference precoding matrix indicated by the first information and the third coefficient corresponding to the uplink sub-band. The third coefficient is determined by the final phase corresponding to the uplink sub-band.

[0225] For example, suppose the third information received by the terminal device indicates the initial phase corresponding to the v-th transport layer. When the terminal device determines the precoding matrix corresponding to the uplink sub-band according to Method 1 above, the terminal device determines the (n+1)th uplink sub-band (i.e., index information is n) and the precoding matrix used by the vth transport layer within the frequency domain range of the uplink data channel as follows: In this way, the third coefficient is... When the terminal device determines the precoding matrix corresponding to the uplink sub-band according to Method 2 above, the terminal device determines the (n+1)th uplink sub-band (i.e., index information is n) and the precoding matrix used by the vth transport layer within the frequency domain range of the uplink data channel as follows: In this way, the third coefficient is...

[0226] The initial phase of each transport layer can be one of the predefined initial phases, and the value of the initial phase is not limited in this embodiment. The predefined initial phases can also be called a set of initial phases or other names, and are not restricted.

[0227] For example, suppose there are M predefined initial phases. Alternatively, there can be M predefined initial phases. Alternatively, there are M+1 predefined initial phases. The value of M can be configured by the network device, determined by the network device based on the capabilities of the terminal device, or predefined; no restrictions are imposed here.

[0228] For the process in which the network device selects the initial phase indicated by the third information from the predefined initial phases, reference may be made to the above process of selecting at least one phase indicated by the second information from the predefined phases, which will not be repeated herein. In addition, the maximum value among the above predefined initial phases can be determined with reference to the value of the above θ max , which will not be elaborated herein either.

[0229] In addition, the number of bits occupied when indicating the initial phase by the third information also refers to the number of bits occupied when indicating the phase by the above second information, which will not be repeated herein either. For example, assuming that the initial phase indicated by the third information is determined from the above M or M+1 predefined initial phases, the number of bits occupied when the third information indicates one initial phase is or The number of bits occupied when the third information indicates a plurality of initial phases is or where maxRank herein is the number of initial phases indicated by the third information, which is determined by the maximum rank supported by the terminal for uplink transmission and / or the rank that the network device indicates the terminal equipment can use at most. For the specific determination process, reference may be made to the process of determining the number of phases indicated by the second information in the above process, which will not be repeated herein either.

[0230] Similarly, in the case that the third information indicates a plurality of initial phases, in order to reduce the indication overhead of the third information, the third information may include the initial phase of the reference transmission layer and the second differential phase of at least one transmission layer among the plurality of transmission layers. The second differential phase is the difference between the initial phase of the transmission layer and the initial phase of the reference transmission layer.

[0231] For example, assuming that the reference transmission layer is the first transmission layer, the initial phase corresponding to the reference transmission layer indicated by the third information is The second differential phase corresponding to the Q-th (Q>1) transmission layer is Then the initial phase corresponding to the Q-th transmission layer may be or Assuming that the initial phase corresponding to the first transmission layer is selected from the above M predefined phases, the number of bits occupied when the third information indicates the initial phase is Assuming that the second differential phase is selected from M d (where M d <M) predefined initial phases, the number of bits occupied when the third information indicates the second differential phase is It can be seen that the overhead required for the third information to indicate the second differential phase is less than the overhead required for the third information to indicate the initial phase corresponding to the reference transmission layer.

[0232] Assume that the initial phase corresponding to the reference transport layer indicated by the third information is determined from M predefined phases, and the first differential phase is from M d If determined from a predefined phase, then the number of bits occupied when the third information indicates the phase corresponding to multiple transport layers is... Wherein, maxRank is the number of phases indicated by the second information, which is determined by the maximum uplink transmission rank supported by the terminal and / or the maximum rank that the network device indicates the terminal device can use.

[0233] In summary, after receiving downlink control information, the terminal device can determine the precoding matrix corresponding to the uplink subband based on the reference precoding matrix indicated by the first information, the phase difference indicated by the second information, and the initial phase corresponding to each transport layer indicated by the third information. Therefore, the network device does not need to indicate the precoding matrix corresponding to each uplink subband through the downlink control information; it can determine the precoding matrix corresponding to the uplink subband solely based on the reference precoding matrix indicated by the first information, the second information, and the initial phase indicated by the third information, thereby reducing the resource overhead required for downlink control information indication.

[0234] The foregoing mainly describes the solutions provided in the embodiments of this application from the perspective of interaction between various devices. It is understood that each device, such as a terminal device or network device, includes corresponding hardware structures and / or software modules to perform the aforementioned functions. Those skilled in the art should readily recognize that, in conjunction with the algorithm steps of the examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware 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.

[0235] This application embodiment can group terminal devices, network devices, etc., into functional modules according to the above method examples. For example, each functional group can correspond to a functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. The grouping of modules in this application embodiment is illustrative and only represents one logical functional grouping; other grouping methods may be used in actual implementation.

[0236] By way of example, embodiments of this application also provide a communication device.

[0237] Please see Figure 7 , Figure 7This is a schematic diagram of the structure of a communication device provided in an embodiment of this application.

[0238] like Figure 7 As shown, the communication device 700 can exist independently or be integrated into other devices. It can communicate with the network devices mentioned above to implement the operations corresponding to the terminal devices or network devices in the above method embodiments.

[0239] The communication device 700 may include a transceiver unit 701 and a processing unit 702. The transceiver unit 701 can implement corresponding communication functions, and the processing unit 702 is used for data processing. The transceiver unit 701 may also be referred to as a communication interface or a communication unit.

[0240] Optionally, when the communication device 700 is used to implement the functions of a terminal device:

[0241] The transceiver unit 701 is used to receive downlink control information from the network device. The downlink control information is used to schedule the uplink data channel, which contains transmission data from one or more transport layers. The uplink data channel includes multiple uplink sub-bands within its frequency domain. The downlink control information carries first information and second information. The first information is used to indicate a reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band and the uplink sub-band corresponding to the reference precoding matrix within the same transport layer.

[0242] The processing unit 702 is used to determine the precoding matrix used by the uplink subband in the frequency domain range of the uplink data channel based on the reference precoding matrix and the second information.

[0243] The transceiver unit 701 is also used to transmit uplink data channels to network devices.

[0244] When the communication device 700 is used to implement the functions of a network device:

[0245] The transceiver unit 701 is used to send downlink control information to the terminal device. The downlink control information is used to schedule the uplink data channel, which contains transmission data of one or more transmission layers. The uplink data channel contains multiple uplink sub-bands in the frequency domain. The downlink control information carries first information and second information. The first information is used to indicate the reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band and the uplink sub-band corresponding to the reference precoding matrix in the same transmission layer.

[0246] The transceiver unit 701 is also used to receive uplink data channels sent by the terminal equipment; wherein the precoding matrix used by the uplink subband of the uplink data channel is determined based on the reference precoding matrix and the second information.

[0247] It should be understood that the corresponding processes performed by each unit have been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0248] The processing unit in the preceding embodiments can be implemented by at least one processor or processor-related circuitry. The transceiver unit 701 can be implemented by a transceiver or transceiver-related circuitry. The transceiver unit can also be referred to as a communication unit or communication interface. The storage unit can be implemented by at least one memory.

[0249] Since the communication device 700 provided in this embodiment can execute the above method, the technical effects it can achieve can be referred to the above method embodiment, and will not be repeated here.

[0250] This application embodiment can divide the communication device into functional modules according to the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in the embodiments of this application is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0251] By way of example, embodiments of this application also provide a communication device.

[0252] Please see Figure 8 , Figure 8 This is a schematic diagram of the hardware structure of a communication device provided in an embodiment of this application.

[0253] The communication device 800 includes a processor 801 coupled to a memory 802. The memory 802 is used to store computer programs or instructions and / or data. The processor 801 is used to execute the computer programs or instructions and / or data stored in the memory 802, so that the methods in the preceding method embodiments are executed.

[0254] Optionally, the communication device 800 may include one or more processors 801.

[0255] Optionally, such as Figure 8 As shown, the communication device 800 may also include a memory 802.

[0256] Optionally, the communication device 800 may include one or more memories 802.

[0257] Alternatively, the memory 802 may be integrated with the processor 801, or it may be set separately.

[0258] like Figure 8As shown, the communication device 800 may further include a transceiver 803 for receiving and / or transmitting signals. For example, the processor 801 is used to control the transceiver 803 to receive and / or transmit signals.

[0259] As one approach, the communication device 800 is used to implement the operations performed by the terminal device or network device in the aforementioned method embodiments.

[0260] This application also provides a communication device, including one or more processors, a memory, and a computer program stored in the memory. The processor executes the computer program to implement the communication method in the above embodiments.

[0261] This application also provides a communication system. Figure 9 This is a schematic diagram of a communication system provided in an embodiment of this application. Figure 9 As shown, the communication system 900 may include a terminal device 910 and a network device 920.

[0262] The network device 920 is used to send downlink control information to the terminal device. The downlink control information is used to schedule the uplink data channel, which contains transmission data of one or more transport layers. The uplink data channel contains multiple uplink sub-bands in the frequency domain. The downlink control information carries first information and second information. The first information is used to indicate the reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band and the uplink sub-band corresponding to the reference precoding matrix in the same transport layer.

[0263] The terminal device 910 is used to determine the precoding matrix used by the uplink subband of the uplink data channel based on the reference precoding matrix indicated by the first information carried in the downlink control information and the second information after receiving the downlink control information.

[0264] Terminal device 910 is also used to transmit uplink data channels to network devices.

[0265] In this embodiment, the terminal device is further configured to execute the method executed by the terminal device in the above embodiments, and the network device is further configured to execute the method executed by the network device in the above embodiments.

[0266] Embodiments of this application also provide a computer-readable storage medium storing computer instructions. When the computer instructions are executed on a communication device, the communication device performs the aforementioned related method steps to implement the communication method in the above embodiments.

[0267] Embodiments of this application also provide a chip system including a memory and a processor, wherein programs / instructions stored in the memory are executed by the processor to implement the communication methods described in the above embodiments.

[0268] Embodiments of this application also provide a computer program product, including a computer program / instructions that, when executed by a processor, implement the communication method described in the above embodiments.

[0269] It is understood that, in order to achieve the above functions, terminal devices and network devices include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware 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 the embodiments of this invention.

[0270] This application embodiment can divide the terminal device and network device into functional modules according to the above method examples. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. The module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0271] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0272] In the embodiments of this application, the functional units can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0273] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as flash memory, portable hard disk, read-only memory, random access memory, magnetic disk, or optical disk.

[0274] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to a terminal device, the method includes: Receive downlink control information from a network device; wherein the downlink control information is used to schedule an uplink data channel, the uplink data channel contains transmission data of at least one transport layer, the uplink data channel contains multiple uplink sub-bands in the frequency domain, the downlink control information carries first information and second information, the first information is used to indicate a reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band among the multiple uplink sub-bands and the uplink sub-band corresponding to the reference precoding matrix in the same transport layer; The uplink data channel is transmitted to the network device; wherein the precoding matrix used for the uplink subband of the uplink data channel is determined based on the reference precoding matrix and the second information.

2. The method according to claim 1, characterized in that, The second information is used to indicate the phase corresponding to each of the at least one transport layer.

3. The method according to claim 2, characterized in that, The second information includes index information of the phase corresponding to each of the at least one transport layer; or, The second information includes the index information of the phases corresponding to the at least one transport layer other than the reference transport layer.

4. The method according to claim 2, characterized in that, The second information includes index information of the phase corresponding to the reference transmission layer and a first differential phase of the at least one transmission layer, wherein the first differential phase is the difference between the phase corresponding to the transmission layer and the phase corresponding to the reference transmission layer.

5. The method according to claim 1, characterized in that, The second information is used to indicate the vector corresponding to each of the at least one transport layer; The vector corresponding to the transport layer includes multiple elements, which correspond to the multiple uplink subbands. One element is used to indicate the phase difference between the uplink subband corresponding to the element and the uplink subband corresponding to the reference precoding matrix in the transport layer.

6. The method according to claim 5, characterized in that, The second information includes a vector-related indication for each of the multiple transport layers; or, The second information includes vector-related indications for each transport layer except the reference transport layer.

7. The method according to claim 5 or 6, characterized in that, The vector corresponding to each transport layer is one of the predefined vector sets.

8. The method according to any one of claims 1-6, characterized in that, The number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

9. The method according to claim 1, characterized in that, The method further includes: Based on the second information, determine the phase difference between any uplink subband among the plurality of uplink subbands and the uplink subband corresponding to the reference precoding matrix in the same transport layer; For any uplink subband, the precoding matrix of the uplink subband is determined based on the phase difference between the reference precoding matrix and the corresponding uplink subband.

10. The method according to claim 9, characterized in that, Determining the precoding matrix of the uplink sub-band based on the phase difference between the reference precoding matrix and the corresponding uplink sub-band includes: The second information indicates at least one phase, and the precoding matrix used by the uplink subband is determined based on the product of the reference precoding matrix and first coefficients, which are determined according to the phase and the index information of the uplink subband; or, The second information indicates at least one vector, and the precoding matrix used by the uplink subband is determined based on the product of the reference precoding matrix and a second coefficient, which is determined based on the vector and the index information of the uplink subband.

11. The method according to any one of claims 1-10, characterized in that, The downlink control information also carries third information, which is used to indicate the initial phase of the precoding matrix corresponding to the plurality of uplink subbands.

12. The method according to claim 11, characterized in that, The method further includes: Based on the second information, determine the phase difference between any uplink subband among the plurality of uplink subbands and the uplink subband corresponding to the reference precoding matrix in the same transport layer; For any uplink subband, the final phase of the uplink subband is determined based on the initial phase and the phase difference of the uplink subband; the precoding matrix of the uplink subband is determined based on the product of the reference precoding matrix and the third coefficient of the uplink subband; the third coefficient is determined by the final phase of the uplink subband.

13. The method according to claim 11 or 12, characterized in that, The initial phase includes initial phases corresponding to multiple transport layers; The third information includes index information of the initial phase of each transport layer; or, The third information includes the initial phase of the reference transport layer and the second differential phase of at least one of the plurality of transport layers, wherein the second differential phase is the difference between the initial phase of the transport layer and the initial phase of the reference transport layer.

14. The method according to any one of claims 1-13, characterized in that, The first information includes the index information of the reference precoding matrix.

15. The method according to claim 14, characterized in that, The predefined precoding matrix is ​​determined based on at least one of the following: the number of antenna ports of the terminal device, the coherence capability of the antenna ports, the maximum uplink transmission rank that the terminal device can support, and the maximum rank that the network device indicates the terminal device can use.

16. The method according to any one of claims 1-15, characterized in that, The reference precoding matrix is ​​the precoding matrix corresponding to an uplink sub-band within the frequency domain range of the uplink bandwidth; or... The reference precoding matrix is ​​the precoding matrix corresponding to an uplink sub-band contained within the frequency domain of the uplink data channel.

17. A communication method, characterized in that, Applied to network devices, the method includes: Sending downlink control information to the terminal device; wherein, the downlink control information is used to schedule the uplink data channel, the uplink data channel contains transmission data of at least one transport layer, the uplink data channel contains multiple uplink sub-bands in the frequency domain, the downlink control information carries first information and second information, the first information is used to indicate a reference precoding matrix, and the second information is used to determine the phase difference between any uplink sub-band among the multiple uplink sub-bands and the uplink sub-band corresponding to the reference precoding matrix in the same transport layer; The terminal device receives the uplink data channel; wherein the precoding matrix used by the uplink subband of the uplink data channel is determined based on the reference precoding matrix and the second information.

18. The method according to claim 17, characterized in that, The second information is used to indicate the phase corresponding to each of the at least one transport layer.

19. The method according to claim 18, characterized in that, The second information includes index information of the phase corresponding to each of the at least one transport layer; or, The second information includes the index information of the phases corresponding to the at least one transport layer other than the reference transport layer.

20. The method according to claim 18, characterized in that, The second information includes index information of the phase corresponding to the reference transmission layer and a first differential phase of the at least one transmission layer, wherein the first differential phase is the difference between the phase corresponding to the transmission layer and the phase corresponding to the reference transmission layer.

21. The method according to claim 17, characterized in that, The second information is used to indicate the vector corresponding to each of the at least one transport layer; The vector corresponding to the transport layer includes multiple elements, which correspond to the multiple uplink subbands. One element is used to indicate the phase difference between the uplink subband corresponding to the element and the uplink subband corresponding to the reference precoding matrix in the transport layer.

22. The method according to claim 21, characterized in that, The second information includes a vector-related indication for each of the multiple transport layers; or, The second information includes vector-related indications for each transport layer except the reference transport layer.

23. The method according to any one of claims 17-22, characterized in that, The number of bits occupied by the second information is determined based on the maximum uplink transmission rank supported by the terminal device and / or the maximum rank that the network device indicates the terminal device can use.

24. The method according to any one of claims 17-23, characterized in that, The downlink control information also carries third information, which is used to indicate the initial phase of the precoding matrix corresponding to the plurality of uplink subbands.

25. The method according to claim 24, characterized in that, The initial phase includes initial phases corresponding to multiple transport layers; The third information includes index information of the initial phase of each transport layer; or, The third information includes the initial phase of the reference transport layer and the second differential phase of at least one of the plurality of transport layers, wherein the second differential phase is the difference between the initial phase of the transport layer and the initial phase of the reference transport layer.

26. A communication device comprising one or more processors, a memory, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method of any one of claims 1-16; and / or to implement the method of any one of claims 17-25.

27. A communication system, characterized in that, It includes a terminal device and a network device, the terminal device being used to perform the method of any one of claims 1-16; and / or to implement the method of any one of claims 17-25.

28. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When executed by a processor, the computer program / instructions implement the method of any one of claims 1-16; and / or implement the method of any one of claims 17-25.

29. A chip system comprising a memory and a processor, characterized in that, When the program / instructions stored in the memory are executed by the processor, they implement the method of any one of claims 1-16; and / or, implement the method of any one of claims 17-25.

30. A computer program product, characterized in that, The computer program product includes: a computer program or instructions that, when executed on a computer, cause the computer to perform the method as claimed in any one of claims 1-16; and / or to implement the method as claimed in any one of claims 17-25.

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