Communication method and device

Abstract

The embodiment of the invention provides a communication method and device, relates to the field of communication, and is used for reducing resource overhead of uplink reference signals. In the method, the terminal equipment can determine M antenna ports and M space layers which actually send uplink reference signals according to received first information, the M space layers are partial space layers in N space layers corresponding to uplink data transmission, and the M antenna ports are in one-to-one correspondence with the M space layers. Therefore, the terminal equipment can realize that the first uplink reference signal is sent through the M antenna ports only on a part of the space layers, namely the M space layers, in the N space layers corresponding to uplink data transmission, so that the resource overhead of the uplink reference signal can be effectively reduced. When the number of space layers corresponding to uplink data transmission is multiplied, the resource overhead of the uplink reference signals can be effectively controlled, so that the saved resources are used for data transmission or used for sending the uplink reference signals of other users, and the resource utilization efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to a communication method and apparatus. Background Technology

[0002] During uplink transmission, the terminal device can send uplink reference signals to the network device through its antenna ports. For example, the terminal device can send DMRS signals to the network device through its demodulation reference signal (DMRS) port for the network device to perform equivalent channel estimation. The number of antenna ports required by the terminal device depends on the spatial layer value or the number of uplink data streams corresponding to the uplink data transmission.

[0003] Currently, with the surge in the number of network users and terminal devices, and the emergence and increasing popularity of new high-bandwidth services such as high-definition video and virtual reality, extremely high demands and challenges are being placed on system capacity and throughput. To meet these challenges, the number of antennas at the transceiver ends of Multiple Input Multiple Output (MIMO) systems is constantly increasing, and signal processing technologies in channel measurement, precoding, and MIMO detection are continuously being enhanced, resulting in a significant increase in the number of data streams in MIMO systems. Network devices need to acquire the channel for each data stream through uplink reference signals. To ensure the quality of channel estimation, the reference signal corresponding to each data stream often occupies orthogonal resources, thus multiplying the number of data streams and consequently multiplying the overhead requirements for uplink reference signals.

[0004] Therefore, how to reduce the resource overhead of the uplink reference signal is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a communication method and apparatus to reduce the resource overhead of uplink reference signals.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] Firstly, a communication method is provided, which can be applied to a terminal device, such as a terminal device or a communication module within a terminal device, or a circuit or chip (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) responsible for communication functions within the terminal device. For ease of description, the following description uses the application of this method to a terminal device as an example. The method includes: receiving first information, and transmitting a first uplink reference signal through M antenna ports on M spatial layers according to the first information. The first information is used to determine the M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers; the M spatial layers are a subset of the N spatial layers corresponding to uplink data transmission, where N and M are integers greater than 0.

[0008] Based on the method described in the first aspect, the terminal device can determine the M antenna ports and M spatial layers for actually transmitting the uplink reference signal according to the received first information. These M spatial layers are a subset of the N spatial layers corresponding to uplink data transmission, and the M antenna ports correspond one-to-one with the M spatial layers. Thus, the terminal device can transmit the uplink reference signal, such as the first uplink reference signal mentioned above, only through the M antenna ports on a subset of the N spatial layers corresponding to uplink data transmission, i.e., the M spatial layers. This effectively reduces the resource overhead of the uplink reference signal. When the number of spatial layers corresponding to uplink data transmission increases exponentially, the resource overhead of the uplink reference signal can be effectively controlled, allowing the saved resources to be used for data transmission or for transmitting uplink reference signals for other users. Within limited resources (such as time-frequency resources), this effectively improves resource utilization efficiency, network capacity, and user experience.

[0009] In one possible design, the first information includes first indication information and second indication information. The first indication information indicates N spatial layers and N antenna ports corresponding one-to-one with the N spatial layers, while the second indication information indicates M spatial layers. Thus, the terminal device can accurately determine the M spatial layers and M antenna ports based on the combined indication of the first and second indication information. This allows the terminal device to subsequently transmit uplink reference signals, such as the aforementioned first uplink reference signal, based on the determined M antenna ports and M spatial layers.

[0010] In one possible design, the first information includes first indication information and second indication information. The first indication information indicates N space layers and M antenna ports, and the second indication information indicates M space layers. Thus, the terminal device can accurately determine the M space layers and M antenna ports based on the combined indication of the first and second indication information. This allows the terminal device to subsequently transmit an uplink reference signal, such as the first uplink reference signal mentioned above, based on the determined M antenna ports and M space layers.

[0011] In one possible design, the second indication information is represented by a bitmap. Each bit in the bitmap indicates whether one of the N spatial layers has transmitted an uplink reference signal. Thus, the terminal device can accurately determine the spatial layer transmitting the uplink reference signal from among the N spatial layers based on the bitmap, for subsequent transmission of the uplink reference signal, such as the first uplink reference signal mentioned above. It is understood that the second indication information can also be represented in other forms, without limitation.

[0012] In one possible design, the first information is used to indicate N spatial layers and N antenna ports corresponding one-to-one with the N spatial layers. The terminal device can determine the N spatial layers and the N antenna ports using the first information.

[0013] In one possible design, the first information is used to indicate N spatial layers and M antenna ports. The terminal device can determine the N spatial layers and M antenna ports using the first information.

[0014] In one possible design, the method described in the first aspect further includes: determining M antenna ports and M spatial layers based on first information and pre-configuration information. The pre-configuration information is used to indicate the M spatial layers. That is, the M spatial layers that actually transmit uplink reference signals out of the N spatial layers are predefined or pre-configured. The terminal device can determine the M spatial layers and M antenna ports based on the first information (used to indicate the N spatial layers and the N antenna ports corresponding one-to-one with the N spatial layers, or used to indicate the N spatial layers and M antenna ports) and the pre-configuration information, without requiring additional signaling to indicate the spatial layers that actually transmit uplink reference signals, thus saving indication overhead.

[0015] In one possible design, the first information is used to indicate the first antenna port combination corresponding to N space layers, and the first antenna port combination contains M antenna ports. In this way, the terminal device can directly and accurately determine the M antenna ports based on the first information.

[0016] In one possible design, N spatial layers correspond one-to-one with N antenna ports, and the N antenna ports are associated with L combinations of antenna ports. Each of the L combinations of antenna ports contains one or more of the N antenna ports. The first combination of antenna ports is one of the L combinations of antenna ports, where L is an integer greater than 0.

[0017] In one possible design, the antenna ports with the same antenna port index as the first antenna port in the N antenna ports correspond to the same space layer.

[0018] Based on the two design schemes described above, N antenna ports can be classified as a first type of antenna port combination, which can contain one or more antenna port combinations, each containing N antenna ports. L antenna port combinations can be classified as a second type of antenna port combination, where each of the L combinations contains fewer than N antenna ports. The first and second types of antenna port combinations are associated; for example, N antenna ports with the same antenna port index as those in the first antenna port combination correspond to the same spatial layer. Thus, M spatial layers and M antenna ports can be implicitly indicated without increasing overhead, effectively reducing indication overhead.

[0019] In one possible design, the first information is used to indicate the uplink precoding matrix. Based on the first information, a first uplink reference signal is transmitted through M antenna ports on M spatial layers, including: transmitting the first uplink reference signal through M antenna ports on M spatial layers according to the uplink precoding matrix. The terminal device can precode the first uplink reference signal according to the uplink precoding matrix to ensure uplink transmission performance.

[0020] Secondly, a communication method is provided. This method can be executed by a network device, by a module applied to the network device (e.g., a processor, chip, or chip system), or by a logical node, logical module, or software capable of implementing all or part of the network device's functions. For ease of description, the following description uses the example of the method being executed by a network device. The method includes: sending first information and receiving a first uplink reference signal. The first information is used to determine M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers; the M spatial layers are a subset of the N spatial layers corresponding to uplink data transmission, where N and M are integers greater than 0; the first uplink reference signal is transmitted through the M antenna ports on the M spatial layers.

[0021] In one possible design, the first information includes first indication information and second indication information; the first indication information is used to indicate N space layers and N antenna ports corresponding one-to-one with the N space layers, and the second indication information is used to indicate M space layers.

[0022] In one possible design, the first information includes first indication information and second indication information. The first indication information is used to indicate N space layers and M antenna ports, and the second indication information is used to indicate M space layers.

[0023] In one possible design, the second indication information is represented by a bitmap. Each bit in the bitmap indicates whether one of the N spatial layers transmits an uplink reference signal. This allows network devices greater flexibility in selecting the spatial layer that transmits the uplink reference signal, providing sufficient freedom to optimally adapt to channel conditions, select the best spatial layer for measurement, and achieve the best performance.

[0024] In one possible design, the first information is used to indicate N spatial layers and N antenna ports corresponding one-to-one with the N spatial layers.

[0025] In one possible design, the first information is used to indicate N space layers and M antenna ports.

[0026] In one possible design, the first information is used to indicate the first antenna port combination corresponding to N space layers, and the antenna ports in the first antenna port combination are M antenna ports.

[0027] In one possible design, N spatial layers correspond one-to-one with N antenna ports, and the N antenna ports are associated with L combinations of antenna ports. Each of the L combinations of antenna ports contains one or more of the N antenna ports. The first combination of antenna ports is one of the L combinations of antenna ports, where L is an integer greater than 0.

[0028] In one possible design, the antenna ports with the same antenna port index as the first antenna port in the N antenna ports correspond to the same space layer.

[0029] In one possible design, the first information is used to indicate the uplink precoding matrix, and the first uplink reference signal is determined based on the uplink precoding matrix. This ensures uplink transmission performance.

[0030] Furthermore, other technical effects of the method described in the second aspect can be referred to the technical effects of the method described in the first aspect, and will not be repeated here.

[0031] Thirdly, a communication device is provided. The communication device includes modules for performing the method as described in the first aspect. For example, a transceiver module and a processing module.

[0032] The transceiver module is used to receive first information and, based on the first information, transmit a first uplink reference signal through M antenna ports on M spatial layers. The first information is used to determine the M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers. The M spatial layers are a subset of the N spatial layers corresponding to the uplink data transmission, where N and M are integers greater than 0.

[0033] In one possible design, the first information includes first indication information and second indication information; the first indication information is used to indicate N space layers and N antenna ports corresponding one-to-one with the N space layers, and the second indication information is used to indicate M space layers.

[0034] In one possible design, the first information includes first indication information and second indication information. The first indication information is used to indicate N space layers and M antenna ports, and the second indication information is used to indicate M space layers.

[0035] In one possible design, the second indication information is represented by a bitmap. The value of each bit in the bitmap indicates whether one of the N spatial layers has sent an uplink reference signal.

[0036] In one possible design, the first information is used to indicate N spatial layers and N antenna ports corresponding one-to-one with the N spatial layers.

[0037] In one possible design, the first information is used to indicate N space layers and M antenna ports.

[0038] In one possible design, the processing module is used to determine M antenna ports and M space layers based on the first information and the pre-configuration information. The pre-configuration information is used to indicate the M space layers.

[0039] In one possible design, the first information is used to indicate the first antenna port combination corresponding to N space layers, and the antenna ports in the first antenna port combination are M antenna ports.

[0040] In one possible design, N spatial layers correspond one-to-one with N antenna ports, and the N antenna ports are associated with L combinations of antenna ports. Each of the L combinations of antenna ports contains one or more of the N antenna ports. The first combination of antenna ports is one of the L combinations of antenna ports, where L is an integer greater than 0.

[0041] In one possible design, the antenna ports with the same antenna port index as the first antenna port in the N antenna ports correspond to the same space layer.

[0042] In one possible design, the first information is used to indicate the uplink precoding matrix. The transceiver module is also used to transmit a first uplink reference signal through M antenna ports on M spatial layers, based on the uplink precoding matrix.

[0043] Optionally, the transceiver module may include a sending module and a receiving module. The sending module implements the sending function of the communication device described in the seventh aspect, and the receiving module implements the receiving function of the communication device described in the third aspect.

[0044] Optionally, the communication device described in the third aspect may further include a storage module storing programs or instructions. When the processing module executes the program or instructions, the communication device can perform the communication method described in the first aspect.

[0045] It should be noted that the communication device described in the third aspect may be a terminal device, a chip (system) or other component or assembly in the terminal device, or a device containing the terminal device. This application does not limit it in this regard.

[0046] Furthermore, the technical effects of the communication device described in the third aspect can be referred to the technical effects of the communication method described in the first aspect, and will not be repeated here.

[0047] Fourthly, a communication device is provided. The communication device includes modules for performing the method described in the second aspect, such as a transceiver module and a processing module.

[0048] The processing module controls the transceiver module to send first information. The transceiver module receives a first uplink reference signal. The first information determines the M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers. The M spatial layers are a subset of the N spatial layers corresponding to the uplink data transmission, where N and M are integers greater than 0. The first uplink reference signal is transmitted through the M antenna ports on the M spatial layers.

[0049] In one possible design, the first information includes first indication information and second indication information; the first indication information is used to indicate N space layers and N antenna ports corresponding one-to-one with the N space layers, and the second indication information is used to indicate M space layers.

[0050] In one possible design, the first information includes first indication information and second indication information. The first indication information is used to indicate N space layers and M antenna ports, and the second indication information is used to indicate M space layers.

[0051] In one possible design, the second indication information is represented by a bitmap; wherein the value of each bit in the bitmap is used to indicate whether one of the N spatial layers sends an uplink reference signal.

[0052] In one possible design, the first information is used to indicate N spatial layers and N antenna ports corresponding one-to-one with the N spatial layers.

[0053] In one possible design, the first information is used to indicate N space layers and M antenna ports.

[0054] In one possible design, the first information is used to indicate the first antenna port combination corresponding to N space layers, and the antenna ports in the first antenna port combination are M antenna ports.

[0055] In one possible design, N spatial layers correspond one-to-one with N antenna ports, and the N antenna ports are associated with L combinations of antenna ports. Each of the L combinations of antenna ports contains one or more of the N antenna ports. The first combination of antenna ports is one of the L combinations of antenna ports, where L is an integer greater than 0.

[0056] In one possible design, the antenna ports with the same antenna port index as the first antenna port in the N antenna ports correspond to the same space layer.

[0057] In one possible design, the first information is used to indicate the uplink precoding matrix, and the first uplink reference signal is determined based on the uplink precoding matrix.

[0058] Optionally, the transceiver module may include a sending module and a receiving module. The sending module implements the sending function of the communication device described in the fourth aspect, and the receiving module implements the receiving function of the communication device described in the fourth aspect.

[0059] Optionally, the communication device described in the fourth aspect may further include a storage module storing programs or instructions. When the processing module executes the program or instructions, the communication device can perform the method described in the second aspect.

[0060] It is understood that the communication device described in the fourth aspect may be a network device, or a chip (system) or other component or part in the network device, or a device containing a network device, and this application does not limit it in this regard.

[0061] Furthermore, the technical effects of the communication device described in the fourth aspect can be referred to the technical effects of the method described in the second aspect, and will not be repeated here.

[0062] Fifthly, a communication device is provided. The communication device includes a processor configured to perform the method described in the first or second aspect.

[0063] In one possible design, the communication device described in the fifth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the fifth aspect and other communication devices.

[0064] In one possible design, the communication device described in the fifth aspect may further include a memory. This memory may be integrated with the processor or disposed separately. The memory may be used to store computer programs and / or data involved in the methods described in the first or second aspect.

[0065] In the embodiments of this application, the communication device described in the fifth aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly disposed in the terminal device, or a device comprising the terminal device; or, the communication device described in the fifth aspect may be the network device described in the second aspect, or a chip (system) or other component or assembly disposed in the network device, or a device comprising the network device.

[0066] Furthermore, the technical effects of the communication device described in the fifth aspect can be referred to the technical effects of the method described in the first or second aspect, and will not be repeated here.

[0067] A sixth aspect provides a communication device. The communication device includes a processor coupled to a memory, the processor being configured to execute a computer program stored in the memory, such that the communication device performs the method described in the first or second aspect.

[0068] In one possible design, the communication device described in the sixth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the sixth aspect and other communication devices.

[0069] In the embodiments of this application, the communication device described in the sixth aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly disposed in the terminal device, or a device comprising the terminal device; or, the communication device described in the sixth aspect may be the network device described in the second aspect, or a chip (system) or other component or assembly disposed in the network device, or a device comprising the network device.

[0070] Furthermore, the technical effects of the communication device described in the sixth aspect can be referred to the technical effects of the method described in the first or second aspect, and will not be repeated here.

[0071] A seventh aspect provides a communication device, comprising: a processor and a memory; the memory being used to store a computer program, which, when executed by the processor, causes the communication device to perform the method described in the first aspect or the second aspect.

[0072] In one possible design, the communication device described in the seventh aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the seventh aspect and other communication devices.

[0073] In the embodiments of this application, the communication device described in the seventh aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly disposed in the terminal device, or a device comprising the terminal device; or, the communication device described in the seventh aspect may be the network device described in the second aspect, or a chip (system) or other component or assembly disposed in the network device, or a device comprising the network device.

[0074] Furthermore, the technical effects of the communication device described in the seventh aspect can be referred to the technical effects of the method described in any of the implementations of the first or second aspect, and will not be repeated here.

[0075] Eighthly, a communication device is provided, comprising: a processor; the processor being coupled to a memory and, after reading a computer program from the memory, executing the method as described in the first or second aspect according to the computer program.

[0076] In one possible design, the communication device described in the eighth aspect may further include a transceiver. This transceiver may be a transceiver circuit or an interface circuit. The transceiver can be used for communication between the communication device described in the eighth aspect and other communication devices.

[0077] In the embodiments of this application, the communication device described in the eighth aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly disposed in the terminal device, or a device comprising the terminal device; or, the communication device described in the eighth aspect may be the network device described in the second aspect, or a chip (system) or other component or assembly disposed in the network device, or a device comprising the network device.

[0078] Furthermore, the technical effects of the communication device described in the eighth aspect can be referred to the technical effects of the method described in the first or second aspect, and will not be repeated here.

[0079] Ninthly, a communication system is provided. The communication system includes: the terminal device described in the first aspect and the network device described in the second aspect.

[0080] In a tenth aspect, a communication chip is provided, wherein instructions are stored that, when the chip is operated on a communication device, cause the communication method as described in the first or second aspect to be implemented.

[0081] Eleventhly, a computer-readable storage medium is provided, comprising: a computer program or instructions; when the computer program or instructions are executed on a computer, the computer causes the computer to perform the method described in the first aspect or the second aspect.

[0082] In a twelfth aspect, a computer program product is provided, comprising a computer program or instructions that, when executed on a computer, cause the computer to perform the method described in the first or second aspect. Attached Figure Description

[0083] Figure 1 A schematic diagram of time-frequency resource mapping for type 1DMRS;

[0084] Figure 2 A schematic diagram of time-frequency resource mapping for type 2DMRS;

[0085] Figure 3 This is a schematic diagram showing the distribution curves of the correlation coefficients of the equivalent channel vectors corresponding to the two spatial layers after precoding.

[0086] Figure 4 A schematic diagram of the equivalent channel correlation corresponding to different spatial layers;

[0087] Figure 5 This application provides a schematic diagram of the architecture of a communication system.

[0088] Figure 6 A schematic diagram illustrating the corresponding modules and functions of a network device and a terminal device provided in this application embodiment;

[0089] Figure 7 A schematic diagram of an O-RAN architecture provided for an embodiment of this application;

[0090] Figure 8 A flowchart illustrating a communication method provided in an embodiment of this application;

[0091] Figure 9 This application provides an illustration of a partial space layer DMRS transmission method. Figure 1 ;

[0092] Figure 10 This application provides an illustration of a partial space layer DMRS transmission method. Figure 2 ;

[0093] Figure 11Schematic diagram of the communication device provided in the embodiments of this application Figure 1 ;

[0094] Figure 12 Schematic diagram of the communication device provided in the embodiments of this application Figure 2 . Detailed Implementation

[0095] For ease of understanding, the technical terms involved in the embodiments of this application will be introduced below.

[0096] 1. Reference signal (RS)

[0097] A reference signal, also known as a pilot signal, is a known signal provided by the transmitter to the receiver for channel estimation or channel sounding. Reference signals can be divided into uplink reference signals and downlink reference signals. Uplink reference signals refer to signals sent from a terminal device to a network device; that is, the transmitter is the terminal device and the receiver is the network device. Uplink reference signals can be used for uplink channel estimation (such as for coherent demodulation and detection in network devices, for calculating precoding, or for determining uplink scheduling), or for uplink channel quality measurement. Downlink reference signals refer to signals sent from a network device to a terminal device; that is, the transmitter is the network device and the receiver is the terminal device. Downlink reference signals can be used for downlink channel estimation (such as for coherent detection and demodulation in terminal devices), downlink channel quality measurement, or cell search.

[0098] Uplink reference signals include sounding reference signal (SRS), demodulation reference signal (DMRS), tracking reference signal (TRS), phase noise tracking reference signal (PTRS), and so on. Downlink reference signals include channel status information reference signal (CSI-RS), DMRS, cell reference signal (CRS), synchronization signal block (SSB), primary synchronization signal (PSS), secondary synchronization signal (SSS), and PTRS, etc.

[0099] 2. Antenna Port

[0100] An antenna port is a logical concept; one antenna port can correspond to one physical transmit antenna or multiple physical transmit antennas. In both cases, the terminal's receiver will not decompose signals from the same antenna port. From the terminal's perspective, regardless of whether the channel is formed by a single physical transmit antenna or by combining multiple physical transmit antennas, the reference signal corresponding to that antenna port defines it. For example, the antenna port corresponding to DMRS is the DMRS port. Each DMRS port corresponds to a spatial layer or data stream, and network devices can obtain channel estimation for that antenna port based on the DMRS. Each antenna port maps to a corresponding time / frequency resource and has its own independent reference signal. One antenna port is essentially one channel, and the terminal can perform channel estimation and data demodulation based on the reference signal corresponding to that antenna port.

[0101] An antenna port, often simply called a port, can be understood as a virtual transmitting antenna (or antenna array) identified by the receiving end, or a spatially distinguishable virtual transmitting antenna (or antenna array). Each virtual antenna corresponds to one antenna port, and each virtual antenna can be a weighted combination of multiple physical antennas. One or more antenna ports can correspond to a reference signal; therefore, each antenna port can be called a port for a reference signal, such as a CSI-RS port, DMRS port, or SRS port.

[0102] In protocols, antenna ports are typically characterized by "antenna port" or "port," but can also be characterized by resources (such as CSI-RS resources, SRS resources, DMRS resources, etc.) or resource groups. A port set contains one or more antenna ports, usually corresponding to one or more resources. The concept of a port set can also be replaced by other names, such as resource group, resource set, pilot resource group, pilot resource set, reference signal resource group, reference signal resource set, port group, antenna port group, antenna port set, or antenna port collection, etc., which are not limited in this application embodiment. In this application embodiment, the port set can also be replaced by "port #A to port #B." Port #A and port #B can be understood as examples of port indices. The antenna ports indicated by port #A to port #B can be understood as antenna ports indexed from #A to #B, and these antenna port indices are consecutive. In this application embodiment, the port set can also be replaced by the index of each antenna port included in the port set. In this case, the antenna ports included in the port set can be antenna ports with consecutive port indices or antenna ports with non-consecutive port indices, without limitation. Different antenna ports can be multiplexed using code division, frequency division, time division, or space division to reduce mutual interference. Each DMRS port corresponds to a space layer / data stream.

[0103] 3. Multiple-input multiple-output (MIMO)

[0104] MIMO is a core technology of Long Term Evolution (LTE) and New Radio (NR) systems. It's an antenna system that uses multiple antennas at both the transmitting and receiving ends to create multiple channels between transmission and reception. A key characteristic of MIMO systems is their extremely high spectral efficiency. By fully utilizing existing spectrum resources, it leverages spatial resources to achieve gains in both reliability and efficiency. Massive MIMO technology uses a large number of antennas to transmit and receive data, enabling it to serve a greater number of users simultaneously, thereby significantly improving spectral efficiency and power efficiency.

[0105] For uplink (UL) transmission, when a terminal device is configured with multiple transmit radio frequency channels, it can perform uplink MIMO transmission using multiple antennas. Furthermore, multiple terminal devices transmitting simultaneously on the same time-frequency resources can also constitute a virtual MIMO system, namely uplink multi-user (MU) MIMO transmission (UL MU-MIMO). In a MIMO system, multiple parallel data streams can be transmitted within the same time-frequency resources using spatial multiplexing, where each data stream can be called a spatial layer. A spatial layer can also be called a data stream, or simply a stream or layer; that is, for uplink multi-antenna transmission, the parallel multiple data streams are called spatial layers or spatial streams. Typically, the number of spatial layers (also called rank, or simply R) corresponding to a terminal device is usually no greater than the number of antennas on the terminal device.

[0106] For a terminal device, in order to effectively ensure the transmission performance of uplink data, precoding is typically performed on the transmitted signals of multiple uplink spatial layers. Assume the data symbol vector transmitted by the terminal is x = [x1, x2, ..., x...]. L ] T , where x l This represents the transmitted data symbol corresponding to the l-th spatial layer. Assuming the precoding matrix is ​​W, the precoded transmitted signal vector can be represented as:

[0107]

[0108] in, This represents the transmitted symbol corresponding to the j-th transmit antenna port. In practical systems, the precoding matrix used by the terminal device in uplink transmission is usually indicated to the terminal device by the network device (e.g., by indicating a precoding matrix from a predefined codebook set via indication signaling). Correspondingly, the network device receives the uplink data transmitted by the terminal device and detects transmitted signals from multiple spatial layers. Detecting signals from multiple spatial layers at the receiving end requires knowing the channels traversed by the multiple data streams. Taking the DMRS as a reference signal as an example, the DMRS can be used to estimate the equivalent channel matrix traversed by the data channel, such as the physical uplink shared channel (PUSCH), or the control channel, such as the physical uplink control channel (PUCCH). Therefore, the DMRS is usually precoded in the same way as the data channel (PUSCH) to ensure that the DMRS and data traverse the same equivalent channel.

[0109] Assuming the DMRS vector transmitted by the transmitter is s, and the transmitted data symbol vector is x, and the DMRS and data undergo the same precoding operation (multiplied by the same precoding matrix P), the corresponding received signal vector at the receiver can be represented as:

[0110] Data signals:

[0111] DMRS:

[0112] Where n represents noise. That is, the equivalent channel experienced by both the data signal and the reference signal (i.e., DMRS) is... The equivalent channel can typically be represented as the synthesized channel matrix at the receiver's spatial layer or antenna port angle after precoding and traversing the channel; that is, the product of H and P. The dimension of the equivalent channel matrix is ​​N. R ×R, where N R Let R be the number of receiving antennas and R be the number of spatial layers. Since the DMRS vector s is known, the receiver can obtain the equivalent channel based on the DMRS vector s. Estimation can be performed using algorithms such as least squares (LS) or minimum mean square error (MMSE) to obtain the equivalent channel. The estimation can then be based on the equivalent channel. The MIMO equalization and subsequent demodulation of the data signal are completed. It can be seen that DMRS is used to estimate the equivalent channel. Its dimension is N R ×R. Therefore, for MIMO transmission with R spatial layers, the required number of DMRS ports is R. For a detailed introduction to DMRS, please refer to the relevant section "4. DMRS" below; it will not be repeated here.

[0113] 4. DMRS

[0114] Currently, the NR protocol supports multiple DMRS types. Different DMRS (configuration) types have different time-frequency resource mapping methods or support different numbers of orthogonal ports. For (configuration) type 1 DMRS, a maximum of 8 orthogonal ports are supported; for (configuration) type 2 DMRS, a maximum of 12 orthogonal ports are supported. A DMRS can occupy at least one orthogonal frequency division multiplexing (OFDM) symbol in the time domain, and its bandwidth in the frequency domain is the same as the scheduling bandwidth of the scheduled data signal. Multiple DMRS symbols corresponding to one DMRS port correspond to one reference signal sequence, and a reference signal sequence includes multiple reference signal sequence elements. The DMRS reference signal sequence can be a gold sequence or a ZC (Zadoff-Chu) sequence. Taking a gold sequence as an example, the nth element in the reference signal sequence can be generated by the following formula:

[0115]

[0116] Wherein, the pseudo-random sequence c(n) can be a gold sequence of length 31, for an output length of M PN The sequence c(n), n = 0, 1, ..., M PN , can be defined as:

[0117] c(n)=(x1(n+N c )+x2(n+N c ))mod 2;

[0118] x1(n+31)=(x1(n+3)+x2(n))mod 2;

[0119] x2(n+31)=(x2(n+3)+x2(n+2)+x2(n+1)+x2(n))mod 2;

[0120] Where, N c =1600. The first m-sequence x1(n) can be initialized as x1(0) = 1, x1(n) = 0, n = 1, 2, ..., 30. The second m-sequence x2(n) is determined by the parameter c. init Initialization. init It can be defined as:

[0121]

[0122] Where l is the index of OFDM symbols contained in a slot. For a slot index within a system frame, It can be configured via higher-level signaling. Related to cell identification, it can usually be equal to cell ID. Right now This is an initialization parameter and can take the value 0 or 1. λ is the code division multiplexing (CDM) group index corresponding to the DMRS port.

[0123] The DMRS reference signal sequence corresponding to a port is mapped to the corresponding time-frequency resource after being multiplied by the corresponding mask sequence according to a preset time-frequency resource mapping rule. For DMRS port p, the m-th reference sequence element r(m) in its corresponding reference signal sequence can be mapped to the index (k,l) according to the following rule. p,μ On the resource element (RE). Where the index is (k, l) p,μ The RE corresponds to an OFDM symbol with index l in the time domain and a subcarrier with index k in the frequency domain. The mapping rule satisfies:

[0124]

[0125]

[0126] k′=0,1;

[0127]

[0128] n = 0, 1, ...;

[0129] l′=0,1;

[0130] Where μ is the subcarrier spacing parameter, To map to index (k, l) p,μ The DMRS modulation symbol corresponding to port p of the RE, The symbol index of the starting OFDM symbol or the symbol index of the reference OFDM symbol occupied by the DMRS modulation symbol. w is the power scaling factor. t (l′) represents the time-domain mask element corresponding to the OFDM symbol with index l′, w f (k′) is the frequency domain mask element corresponding to the subcarrier with index k′, m=2n+k′, and Δ is the subcarrier offset factor.

[0131] The NR protocol defines two types of DMRS configuration methods: configuration type 1 (type 1 DMRS) and configuration type 2 (type 2 DMRS). In the mapping rules of type 1 DMRS, DMRS port p corresponds to w... f (k′), w t The values ​​of (l′) and Δ can be determined according to Table 1.

[0132] Table 1

[0133]

[0134] In the mapping rules of type 2 DMRS, the DMRS port p corresponds to w f (k′), w t The values ​​of (l′) and Δ can be determined according to Table 2.

[0135] Table 2

[0136]

[0137] Where λ is the index of the code division multiplexing group (also known as the orthogonal multiplexing group) to which the DMRS port p belongs. DMRS ports within the same orthogonal multiplexing group occupy the same time and frequency resources.

[0138] According to the above time-frequency resource mapping rules Figure 1 A schematic diagram of time-frequency resource mapping for type 1DMRS, as shown below. Figure 1 As shown, for a single-symbol DMRS (corresponding to l′=0), the DMRS resource occupies one OFDM symbol, supporting a maximum of 4 DMRS ports. These 4 DMRS ports are divided into two code division multiplexing groups (CDM groups), for example, CDM group 0 and CDM group 1. CDM group 0 contains DMRS port 0 and DMRS port 1; CDM group 1 contains DMRS port 2 and DMRS port 3. CDM group 0 and CDM group 1 are frequency division multiplexed (i.e., mapped onto different frequency domain resources). The DMRS ports within a CDM group are mapped onto the same time-frequency resources. The reference signals corresponding to the DMRS ports within a CDM group are distinguished using an orthogonal cover code (OCC) to ensure the orthogonality of the DMRS ports within the CDM group, thereby suppressing interference between DMRS transmitted on different antenna ports.

[0139] For example, such as Figure 1As shown in (a), DMRS ports 0 and 1 are located within the same resource particles (REs) and are mapped in the frequency domain in a comb-like manner, meaning that adjacent frequency domain resources occupied by DMRS ports 0 and 1 are separated by one subcarrier. For a DMRS port, the two adjacent occupied REs correspond to an OCC codeword sequence of length 2. For example, for subcarriers 0 and 2, DMRS ports 0 and 1 use a set of OCC codeword sequences of length 2 (+1+1 and +1-1). Similarly, DMRS ports 2 and 3 are located within the same REs and are mapped in the frequency domain in a comb-like manner onto the unoccupied REs of DMRS ports 0 and 1. For subcarriers 1 and 3, DMRS ports 2 and 3 use a set of OCC codeword sequences of length 2 (+1+1 and +1-1).

[0140] For dual-symbol DMRS, DMRS resources occupy two OFDM symbols, supporting a maximum of eight DMRS ports. These eight DMRS ports are divided into two code division multiplexing (CDM) groups, such as CDM group 0 and CDM group 1. CDM group 0 includes DMRS port 0, DMRS port 1, DMRS port 4, and DMRS port 5; CDM group 1 includes DMRS port 2, DMRS port 3, DMRS port 6, and DMRS port 7. CDM group 0 and CDM group 1 are frequency division multiplexing (FDM), and the reference signals corresponding to the DMRS ports within a CDM group are distinguished using OCC (Optical Code Classification).

[0141] For example, such as Figure 1 As shown in (b), DMRS ports 0, 1, 4, and 5 are located within the same RE and are mapped in the frequency domain in a comb-like manner. That is, adjacent frequency domain resources occupied by DMRS ports 0, 1, 4, and 5 are separated by a subcarrier. For a single DMRS port, the two adjacent subcarriers and two OFDM symbols occupy a single OCC codeword sequence of length 4. For example, for subcarriers 0 and 2 corresponding to OFDM symbols 1 and 2, DMRS ports 0, 1, 4, and 5 can use a set of OCC codeword sequences of length 4 (+1+1+1+1 / +1+1-1-1 / +1-1+1-1 / +1-1-1+1).

[0142] Similarly, DMRS ports 2, 3, 6, and 7 are located within the same RE and are mapped in the frequency domain in a comb-like manner onto the unoccupied subcarriers of DMRS ports 0, 1, 4, and 5. For subcarriers 1 and 3 corresponding to OFDM symbols 1 and 2, DMRS ports 2, 3, 6, and 7 can use a set of OCC codeword sequences of length 4 (+1+1+1+1 / +1+1-1-1 / +1-1+1-1 / +1-1-1+1).

[0143] Figure 2 A schematic diagram of time-frequency resource mapping for type 2DMRS, as shown below. Figure 2 As shown, for single-symbol type 2 DMRS, DMRS resources occupy one OFDM symbol, supporting a maximum of 6 DMRS ports. These 6 DMRS ports are divided into 3 code division multiplexing groups, such as CDM group 0, CDM group 1, and CDM group 2. Frequency division multiplexing (i.e., mapping to different frequency domain resources) is used between CDM groups; specifically, frequency division multiplexing is used between CDM group 0, CDM group 1, and CDM group 2. The reference signals corresponding to the DMRS ports within a CDM group are mapped to the same time-frequency resources, and the orthogonality of the reference signals corresponding to the DMRS ports within a CDM group is guaranteed by OCC. Specifically, CDM group 0 contains DMRS port 0 and DMRS port 1; CDM group 1 contains DMRS port 2 and DMRS port 3; and CDM group 2 contains DMRS port 4 and DMRS port 5. For a DMRS port, its corresponding DMRS reference signal is mapped in the frequency domain into multiple resource sub-blocks containing two consecutive subcarriers, with adjacent resource sub-blocks spaced four subcarriers apart in the frequency domain.

[0144] For example, such as Figure 2As shown in (a), DMRS port 0 and DMRS port 1 are located within the same RE and are mapped in a comb-like manner. For example, taking a frequency domain resource granularity of one resource block (RB) as an example, DMRS port 0 and DMRS port 1 occupy subcarriers 0, 1, 6, and 7; DMRS port 2 and DMRS port 3 occupy subcarriers 2, 3, 8, and 9; and DMRS port 4 and DMRS port 5 occupy subcarriers 4, 5, 10, and 11. For two DMRS ports contained within a CDM group, there are corresponding OCC codeword sequences of length 2 (+1+1 and +1-1) in two adjacent subcarriers.

[0145] For dual-symbol type 2 DMRS, DMRS resources occupy two OFDM symbols, supporting a maximum of 12 DMRS ports. These 12 DMRS ports are divided into three CDM groups, such as CDM group 0, CDM group 1, and CDM group 2. Frequency division multiplexing (FDM) is used between CDM groups, meaning that CDM group 0, CDM group 1, and CDM group 2 use FDM. The reference signals corresponding to the DMRS ports within a CDM group are mapped to the same time-frequency resources, and the orthogonality of the reference signals corresponding to the DMRS ports within a CDM group is guaranteed by OCC (Optical Cross-Channel Combination). Specifically, CDM group 0 can contain DMRS port 0, DMRS port 1, DMRS port 6, and DMRS port 7; CDM group 1 can contain DMRS port 2, DMRS port 3, DMRS port 8, and DMRS port 9; and CDM group 2 can contain DMRS port 4, DMRS port 5, DMRS port 10, and DMRS port 11. For a DMRS port, its corresponding DMRS reference signal is mapped in the frequency domain into multiple resource sub-blocks containing two consecutive subcarriers, with adjacent resource sub-blocks spaced four subcarriers apart in the frequency domain.

[0146] Specifically, such as Figure 2As shown in (b), the DMRS ports contained in a CDM group are located within the same RE and are mapped in the frequency domain in a comb-like manner. For example, taking a frequency domain resource granularity of 1 RB, DMRS ports 0, 1, 6, and 7 occupy subcarriers 0, 1, 6, and 7 corresponding to OFDM symbols 1 and 2. DMRS ports 2, 3, 8, and 9 occupy subcarriers 2, 3, 8, and 9 corresponding to OFDM symbols 1 and 2. DMRS ports 4, 5, 10, and 11 occupy subcarriers 4, 5, 10, and 11 corresponding to OFDM symbols 1 and 2. For a CDM group containing 4 DMRS ports, there is an OCC codeword sequence of length 4 in the two adjacent subcarriers corresponding to the 2 OFDM symbols (+1+1+1+1 / +1+1-1-1 / +1-1+1-1 / +1-1-1+1).

[0147] Based on the above introduction to DMRS, for uplink data transmission, network devices can send indication information to terminal devices, such as downlink control information (DCI), which indicates the scheduling information corresponding to the uplink data channel (such as PUSCH). The DCI may include the number of spatial layers (i.e., rank) corresponding to the uplink data transmission and the corresponding DMRS port information.

[0148] Specifically, the DCI signaling may include an antenna port field to indicate the corresponding DMRS port index. Different rank values ​​can correspond to different DMRS port index tables. For uplink transmissions with a spatial layer number of R, the corresponding number of DMRS ports is also R.

[0149] Taking single-symbol type 1 DMRS as an example, when the transport precoding matrix is ​​not activated, the DMRS port index tables corresponding to rank = 1-4 are shown in Tables 3-6, with a maximum number of symbols or length of 1 (maxLength = 1). Taking double-symbol type 1 DMRS as an example, when the transport precoding matrix is ​​not activated, the DMRS port index tables corresponding to rank = 1-4 are shown in Tables 7-10, with a maximum number of symbols or length of 2 (maxLength = 2). The terminal device can select the corresponding DMRS port index table based on the indicated rank value, thereby determining the indicated port index.

[0150] Table 3

[0151]

[0152] Table 4

[0153]

[0154] Table 5

[0155]

[0156] Table 6

[0157]

[0158] Table 7

[0159]

[0160]

[0161] Table 8

[0162]

[0163] Table 9

[0164]

[0165] Table 10

[0166]

[0167] For example, suppose the network device configures the DMRS type for the terminal device as dmrs-type=1, and the maximum number of DMRS symbols is 2. The network device uses indication information, specifically the DCI indicating that the current uplink PUSCH scheduling rank is 2, and the corresponding DMRS antenna port field is 0. Based on Table 8, it can be determined that the corresponding DMRS ports are those with port indices 0 and 1. Therefore, the terminal device can... Figure 1 Channel estimation is performed on the time-frequency resources corresponding to DMRS port 0 and DMRS port 1.

[0168] 5. Codebook

[0169] For uplink multi-antenna transmission, it can be categorized into full coherent transmission, partially coherent transmission, and non-coherent transmission based on the capabilities of the terminal equipment. Full coherent transmission means that all antenna ports can perform coherent transmission. For example, all antenna ports can guarantee synchronous calibration. In the precoding matrix corresponding to full coherent transmission, each antenna port is associated with all spatial layers. For instance, the precoding matrix used is specifically represented by all non-zero elements in each row. Partial coherent transmission means that only some antenna ports can perform coherent transmission; the set of antennas that can perform coherent transmission is called a coherent antenna port group. Antenna ports in a coherent antenna port group can guarantee synchronous calibration. Non-coherent transmission means that none of the antenna ports can perform coherent transmission. An antenna port group is associated with only one spatial layer. For example, Table 11 shows the precoding matrix used for two-layer transmission with 4 antenna ports, i.e., the precoding matrix used for 4-antenna port transmission when rank=2. Different transmission precoding matrix indicator (TPMI) indices correspond to different precoding matrices. Specifically, TPMI matrix indices 0-5 correspond to noncoherent transmission precoding matrices, TPMI indices 6-13 correspond to partially coherent transmission precoding matrices, and the remaining TPMI indices (i.e., 14-21) correspond to fully coherent transmission precoding matrices.

[0170] Table 11

[0171]

[0172] For example, Table 12 shows the precoding matrix used for four-antenna port transmission at rank=4. In this table, TPMI index 0 is the non-phase interferometry coding matrix, TPMI indices 1-2 are the partial phase interferometry coding matrices, and TPMI indices 3-4 are the full phase interferometry coding matrices.

[0173] Table 12

[0174]

[0175]

[0176] Taking a terminal device with uplink 4-antenna transmission capability for 2 spatial layers (rank=2) as an example, the precoding matrices under different coherent transmission capabilities are shown in Table 11. Taking the incoherent transmission precoding matrix as an example, each spatial layer is transmitted through one of the 4 transmit antennas, which is equivalent to transmitting the data stream through antenna selection. For example, for the precoding matrix with index 0, the data corresponding to the first spatial layer is transmitted through the first transmit antenna, and the data corresponding to the second spatial layer is transmitted through the second transmit antenna.

[0177] Therefore, based on the precoding matrices for uplink transmission shown in Table 11 or Table 12 above, the network device can select an appropriate uplink transmission layer number according to the measured uplink channel information, select an appropriate precoding matrix from the codebook corresponding to that uplink transmission layer number, and thus indicate the determined uplink transmission layer number and TPMI index to the terminal device via DCI. After obtaining the DCI, the terminal device can determine a codebook as shown in Table 11 or Table 12 above based on the DCI, and then determine the precoding matrix from the codebook according to the TPMI. This precoding matrix is ​​the precoding matrix configured by the network device for uplink transmission.

[0178] It is understandable that for uplink transmission (especially for partially coherent and incoherent transmission), due to low precoding precision, the equivalent channel vectors corresponding to different spatial layers after precoding still exhibit high correlation. For example, consider the distribution curves of the correlation coefficients of the equivalent channel vectors corresponding to two spatial layers after precoding using the precoding matrices corresponding to TPMI indices 0-5 in Table 11. Figure 3 As shown, the horizontal axis represents the correlation coefficient (corr-factor), and the vertical axis represents the cumulative distribution function (CDF). Based on Figure 3 It can be seen that the average correlation coefficient of the equivalent channel vectors corresponding to the two spatial layers is about 0.7, and the maximum correlation coefficient can reach more than 0.9.

[0179] Based on the above implementation, utilizing the equivalent channels corresponding to different spatial layers after uplink precoding (i.e., the above-mentioned...) Based on the correlation between spatial layers, terminal devices can transmit only the antenna ports corresponding to a portion of the spatial layers during uplink data transmission, such as transmitting only the DMRS ports corresponding to a portion of the spatial layers (i.e., transmitting DMRS only through the DMRS ports corresponding to a portion of the spatial layers). Network devices can measure the equivalent channels corresponding to a portion of the spatial layers. Furthermore, network devices can utilize the spatial correlation of the equivalent channels between ports, such as using the spatial correlation matrix between channel ports for interpolation recovery, to obtain the equivalent channels corresponding to other spatial layers.

[0180] For example, taking DMRS as the reference signal, such as Figure 4 As shown, for uplink transmission with rank=4 (the four spatial layers are spatial layer #0 to spatial layer #3), based on the traditional scheme, the terminal device needs to send DMRS resources corresponding to four DMRS ports (port #0 to port #3) to the network device. These four DMRS ports need to be mapped to different frequency domain resources, different time domain resources, or occupy different code domain resources to achieve orthogonality or low interference. Specifically, spatial layers #0 to #3 can correspond one-to-one with ports #0 to #3; for example, spatial layer #0 can correspond to port #0, spatial layer #1 can correspond to port #1, spatial layer #2 can correspond to port #2, and spatial layer #3 can correspond to port #3.

[0181] Based on the spatial correlation of the equivalent channel between ports, the terminal device only needs to transmit the two DMRS ports corresponding to a portion of the spatial layer. For example, the terminal device only needs to transmit the two DMRS ports corresponding to spatial layer #0 and spatial layer #2, namely port #0 and port #2. The network device can measure only the equivalent channel corresponding to spatial layer #0 and spatial layer #2, and utilize the spatial correlation of the equivalent channel between ports. For example, spatial interpolation can be used to obtain the corresponding equivalent channel of spatial layer #1 and spatial layer #3. In this way, the DMRS resource overhead can be halved. The embodiments of this application can be based on this implementation principle to reduce the resource overhead of uplink reference signals, such as DMRS. The specific implementation can be referred to below. Figure 8 The relevant information about the communication method shown will not be elaborated here.

[0182] In uplink transmission, terminal devices can send uplink reference signals to network devices through their antenna ports. For example, a terminal device can send DMRS signals through its DMRS port for the network device to perform equivalent channel estimation. The number of antenna ports required by the terminal device depends on the spatial layer value or the number of uplink data streams corresponding to the uplink data transmission. Currently, with the surge in the number of network users or terminal devices, and the emergence and increasing popularity of new high-bandwidth services such as high-definition video and virtual reality, extremely high demands and challenges are being placed on system capacity or throughput. To meet these challenges, the number of antennas at the transceiver ends of MIMO systems is constantly increasing, and signal processing technologies in channel measurement, precoding, and MIMO detection are also continuously improving, resulting in a significant increase in the number of data streams in MIMO systems. Network devices need to obtain the channel for each data stream through the uplink reference signal. To ensure the quality of channel estimation, the reference signal corresponding to each data stream often occupies orthogonal resources, thus multiplying the number of data streams and consequently increasing the overhead requirements for the uplink reference signal.

[0183] For example, with future ultra-large-scale antenna arrays, network devices can have 256 or more antennas, each terminal device can have 8 or 16 antennas, and the network devices can support more than 48 data streams. Based on the above... Figure 1 and Figure 2 As the introduction states, in order to ensure orthogonality or low interference between DMRS ports, different DMRS ports need to occupy different resources for multiplexing (frequency domain resources / code domain resources, etc.). The increased demand for DMRS ports will also lead to a significant increase in the overhead of DMRS during uplink data transmission, such as PUSCH transmission.

[0184] like Figure 1 As shown, currently, type 1 DMRS can support the mapping of 4 DMRS ports by occupying 1 OFDM symbol, thus supporting a maximum rank of 4. When the transmission rank is 8, 2 DMRS symbols are required to achieve the mapping of 8 DMRS ports; when the transmission rank is 16, 4 symbols are required. However, the increased DMRS resource overhead will directly encroach on the resources available for data transmission, or encroach on the resources for other users (such as other terminal devices) to send DMRS data, thus leading to a loss of capacity for users or the network.

[0185] Therefore, how to reduce the resource overhead of the uplink reference signal is an urgent problem to be solved.

[0186] In summary, to address the aforementioned technical problems, this application proposes the following technical solutions to reduce the resource overhead of uplink reference signals.

[0187] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0188] The technical solutions of this application embodiment can be applied to various communication systems, such as Bluetooth systems, wireless fidelity (WiFi) systems, long-range radio (LoRa), vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, machine-to-machine (M2M) communication systems, machine-type communication (MTC), Internet of Things (IoT) communication systems, fourth-generation (4G) communication systems such as long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, worldwide interoperability for microwave access (WiMAX) communication systems, fifth-generation (5G) communication systems such as NR systems, MIMO systems related to the 3rd generation partnership project (3GPP), and future communication systems, etc. The method provided in this application can also be applied to non-terrestrial network (NTN) systems such as inter-satellite communication and satellite communication.

[0189] In a communication system, a device can send signals to or receive signals from another device. These signals can include information, signaling, or data. The term "device" can also be replaced with entities, network entities, communication equipment, communication modules, nodes, communication nodes, etc.

[0190] This application will present various aspects, embodiments, or features relating to systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that individual systems may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these approaches are also possible.

[0191] Furthermore, in the embodiments of this application, the words "exemplary," "for example," etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0192] In the embodiments of this application, the terms "information," "signal," "message," "channel," and "signaling" may sometimes be used interchangeably. It should be noted that, without emphasizing their distinction, their intended meanings are consistent. Similarly, "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing their distinction, their intended meanings are consistent. Furthermore, the " / " mentioned in this application can be used to indicate an "or" relationship. It is understood that in this application, "instruction" can include direct instruction, indirect instruction, explicit instruction, and implicit instruction. When describing an instruction information used to indicate A, it can be understood that the instruction information carries A, directly indicates A, or indirectly indicates A.

[0193] In this embodiment, the information indicated by the instruction information is called the information to be instructed. In specific implementations, there are many ways to indicate the information to be instructed, such as, but not limited to, directly indicating the information to be instructed, such as the information to be instructed itself or its index; or indirectly indicating the information to be instructed by indicating other information, wherein there is an association between the other information and the information to be instructed. Alternatively, only a part of the information to be instructed may be indicated, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent.

[0194] The information to be instructed can be sent as a whole or divided into multiple sub-information messages, and the sending period and / or timing of these sub-information messages can be the same or different. This application does not limit the specific sending method. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the transmitting device by sending configuration information to the receiving device.

[0195] In the embodiments of this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which may include direct transmission via the air interface or indirect transmission by other units or modules via the air interface. "Receive information from YY" can be understood as the source of the information being YY, which may include direct reception from YY via the air interface or indirect reception from YY by other units or modules via the air interface. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface. In other words, sending and receiving can occur between devices, such as between network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via a bus, wiring, or interface.

[0196] In the embodiments of this application, "indicating antenna port" can also be "indicating antenna port index" and "antenna port" can also be "antenna port index".

[0197] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0198] To facilitate understanding of the embodiments of this application, let's first take... Figure 5 The communication system illustrated herein is used as an example to illustrate a communication system applicable to embodiments of this application. For example, Figure 5 This is a schematic diagram illustrating one possible, non-limiting communication system. For example... Figure 5 As shown, the communication system 1000 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 1000 may also include an Internet 300. The RAN 100 includes at least one RAN node (e.g., Figure 5 110a and 110b (collectively referred to as 110) and at least one terminal (such as Figure 5 RAN 100, denoted as RAN 120a-120j, is collectively referred to as RAN 120. RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment. Figure 5(Not shown in the image). Terminal 120 is connected to RAN node 110 wirelessly. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network equipment in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions.

[0199] RAN 100 can be a 3GPP-related cellular system, such as a 4G, 5G mobile communication system, or a future-oriented evolution system. RAN 100 can also be an open access network (open RAN, O-RAN or ORAN), a cloud radio access network (CRAN), or a Wi-Fi system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0200] RAN node 110, sometimes also referred to as network equipment, access network equipment, RAN entity, or access node, constitutes part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in the communication system 1000 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative, for example... Figure 5 Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminals 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes referred to as communication devices, for example... Figure 5 Network elements 110a and 110b can be understood as communication devices with base station functions, while network elements 120a-120j can be understood as communication devices with terminal functions.

[0201] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a Wi-Fi system, etc. Figure 5 110a), micro base stations or indoor stations (such as Figure 5The RAN node can be a relay node or donor node (as described in section 110b), or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in V2X technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node can also be equipped with communication modules, circuits, or chips that perform corresponding communication functions. The RAN node can also be configured with program instructions for performing corresponding communication functions and corresponding program instructions. The RAN node in this application can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0202] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0203] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meanings. For example, in an O-RAN system, CU can also be called an O-RAN central unit (O-CU) (i.e., an open CU), DU can also be called an O-RAN distributed unit (O-DU), CU-CP can also be called an O-RAN central unit control plane (O-CU-CP), CU-UP can also be called an O-RAN central unit user plane (O-CU-UP), and RU can also be called an O-RAN radio unit (O-RU). For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0204] In this embodiment, the form of the network device is not limited. The device used to implement the function of the network device can be the network device itself, or it can be a device that supports the network device in implementing the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device.

[0205] Terminal devices can be devices or modules that access the aforementioned communication systems and possess corresponding communication functions. Terminal devices can include various devices with wireless communication capabilities, which can be used to connect people, objects, machines, etc. Terminal devices can be widely applied in various scenarios, such as: cellular communication, D2D, V2X, peer-to-peer (P2P), M2M, MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, etc. Terminal devices can be terminals in any of the above scenarios, such as MTC terminals, IoT terminals, etc. Terminal equipment can be 3GPP standard user equipment (UE), terminal, fixed equipment, mobile station equipment or mobile equipment, subscriber unit, handheld device, vehicle-mounted equipment, wearable device, cellular phone, smartphone, session initiation protocol (SIP) phone, wireless data card, personal digital assistant (PDA), computer, tablet computer, laptop computer, wireless modem, handset, laptop computer, computer with wireless transceiver capability, smart book, vehicle, satellite, global positioning system (GPS) equipment, target tracking equipment, aircraft (e.g., drones, helicopters, multiple helicopters, four helicopters, or airplanes), boat, remote control equipment, smart home equipment, industrial equipment, transportation vehicles with wireless communication capability, communication modules, roadside units (RSUs) with terminal functionality, or devices built into the above-mentioned equipment (e.g., communication modules, modems, or chips in the above-mentioned equipment), or other processing devices connected to a wireless modem. The terminal device can also be other devices with terminal device functions. For example, the terminal device can also be a device that performs the terminal device function in D2D communication.

[0206] The embodiments of this application do not limit the form of the terminal device. The device used to implement the functions of the terminal device can be the terminal device itself; it can also be a device that supports the terminal device in implementing the functions, such as a chip system. This device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of this application, the chip system can be composed of chips, or it can include chips and other discrete devices. The terminal device typically has a communication module, circuit, or chip that performs the corresponding communication functions. The terminal device can also be configured with program instructions for performing the corresponding communication functions.

[0207] In this communication system, the terminal device can determine the M antenna ports and M spatial layers for actually transmitting the uplink reference signal based on the received first information. These M spatial layers are a subset of the N spatial layers corresponding to uplink data transmission, and each of the M antenna ports corresponds one-to-one with one of the M spatial layers. Thus, the terminal device can transmit the uplink reference signal through the M antenna ports only on a subset of the N spatial layers corresponding to uplink data transmission, i.e., the M spatial layers, as described above as the first uplink reference signal. This effectively reduces the resource overhead of the uplink reference signal. When the number of spatial layers corresponding to uplink data transmission increases exponentially, the resource overhead of the uplink reference signal can be effectively controlled, allowing the saved resources to be used for data transmission or for transmitting uplink reference signals for other users. Within the limited resource constraints (such as time-frequency resources), this effectively improves resource utilization efficiency, network capacity, and user experience.

[0208] The corresponding modules and functions of the above network devices and terminal devices are as follows: Figure 6 As shown, network devices and terminal devices may include a radio resource control (RRC) module, a medium access control (MAC) module, and a physical layer (PHY) module. Network devices and terminal devices can exchange RRC signaling through the RRC module; they can exchange MAC-control element (MAC-CE) signaling through the MAC module; they can exchange uplink or downlink control signaling through the PHY module, such as PUCCH and physical downlink control channel (PDCCH); and they can exchange uplink or downlink data signaling through the PHY module, such as PUSCH and physical downlink shared channel (PDSCH).

[0209] Figure 7This is a schematic diagram of an O-RAN architecture provided in an embodiment of this application, as shown below. Figure 7 As shown, the network elements included may be: Service Management and Orchestration Framework (SMO), Non-Real-Time RAN Intelligent Controller (Non-RT RIC), Near-Real-Time RAN Intelligent Controller (Near-RT RIC), O-CU, O-CU-CP, O-CU-UP, O-DU, O-RU, and (O-RAN Cloud, O-Cloud).

[0210] Among them, SMO: Its function is similar to network management, and it is mainly responsible for the operation, maintenance and management of each communication module in the O-RAN system.

[0211] Non-RT RIC: Used for non-real-time intelligent management of RAN functions, enabling AI / ML workflows including model training and model updates, and guiding applications / functions in the Near-RT RIC based on policies. The Non-RT RIC is located in the SMO module.

[0212] Near-RT RIC: Used to achieve near real-time intelligent management of RAN. Through data collection and related operations on the E2 interface, it enables near real-time control and optimization of O-RAN modules and resources.

[0213] O-CU: Used to implement the RRC layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and other control functions in the 3GPP standard.

[0214] O-CU-CP: Similar to CU-CP in the NR system, it is used to implement the functions of the RRC layer and the control plane functions of the PDCP layer, and is part of O-CU.

[0215] O-DU: Based on low-layer function segmentation, it is used to implement the radio link control (RLC) layer, MAC layer, and higher physical layer (higher PHY) in the 3GPP standard. Among them, the higher physical layer functions include one or more of the following: forward error correction (FEC) encoding / decoding, scrambling / descrambling, or modulation / demodulation.

[0216] O-RU: Based on low-layer function segmentation, it is used to implement lower physical layer (Lower PHY) functions and radio frequency (RF) functions in the 3GPP standard. The low physical layer functions include one or more of the following: Fast Fourier Transform (FFT) / Inverse Fast Fourier Transform (iFFT), digital beamforming, or extraction and filtering of the Physical Random Access Channel (PRACH). It is similar to the Transmission Reception Point (TRP) or Remote Radio Head (RRH) in 3GPP, but includes low physical layer functions such as FFT / iFFT or PRACH extraction.

[0217] O-Cloud: As a cloud computing platform, it includes physical infrastructure nodes for hosting O-RAN functions such as RAN intelligent controllers (RIC), O-DU, etc., and supports software components (such as operating systems, virtual machine monitoring, container runtimes), management and orchestration functions.

[0218] Figure 7 The included interfaces are: A1 interface, E1 interface, E2 interface, O1 interface, O2 interface, open fronthaul control user synchronization plane (open FH CUS-Plane) interface, open fronthaul management plane (open FH M-Plane) interface, F1-c interface, F1-u interface, X2-c interface, X2-u interface, NG-u interface, Xn-u interface, Xn interface, NG-c interface, etc.

[0219] The A1 interface is the interface between the Non-RT RIC and the Near-RT RIC, used for intelligent and dynamic control of radio resources within the O-RAN. The Non-RT RIC provides policies, rich information, and ML model updates to the Near-RT RIC through the A1 interface, while the Near-RT RIC provides policy feedback to the Non-RT RIC through the A1 interface.

[0220] E2 Interface: An open interface between two endpoints used to connect the Near-RT RIC and the RAN node. The RAN node can include, for example, CU and DU in 5G, O-RAN compatible eNB in ​​4G, O-CU (O-CU-CP and / or O-CU-UP) and / or O-DU in O-RAN, etc. The RIC can obtain data collection and feedback from the RAN node through the E2 node, and the RAN node can obtain control feedback from the Near-RT RIC through the E2 node.

[0221] O1 Interface: The interface between the management entity in the SMO and the O-RAN module, used for operation management. FCAPS management, software management, and file management are implemented through this interface.

[0222] O2 Interface: The interface between the SMO and the infrastructure management framework that supports O-RAN virtual network functionality.

[0223] The open FH CUS-plane interface includes a control plane (C-Plane), a user plane (U-Plane), and a synchronization plane (S-Plane). The control plane is used for real-time control between the O-DU and O-RU, such as transmitting beamforming weights from the O-DU to the O-RU or performing power control from the O-DU to the O-RU. The user plane is used to transmit communication data between the DU and RU for access network devices and terminals. The synchronization plane is used by the O-DU to provide clock synchronization for the O-RU.

[0224] As you can understand, the above provides an introduction to the A1 interface, E2 interface, O1 interface, O2 interface, and open FH CUS-Plane interface. Figure 7 For information on other interfaces such as the E1 interface, open FH M-Plane interface, F1-c interface, F1-u interface, X2-c interface, X2-u interface, NG-u interface, Xn-u interface, Xn interface, and NG-c interface, please refer to existing technologies; they will not be elaborated upon here.

[0225] It is understandable that the above Figures 5-7 This is a simplified illustration for ease of understanding only; other devices, modules, or chips may also be included. Figures 5-7 It was not drawn.

[0226] For ease of understanding, the following will combine... Figures 8-10 The communication method provided in the embodiments of this application will be described in detail.

[0227] For example, Figure 8 This is a flowchart illustrating the communication method provided in an embodiment of this application. It can be understood that the embodiments of this application use... Figure 5 The network device and terminal device shown are illustrated as examples of the execution entities in this interaction illustration, but the embodiments of this application do not limit the execution entities in the interaction illustration. For example, the method executed by the network device in this application embodiment can also be implemented by a module (e.g., circuit, processor, chip, or chip system, etc.) in the network device, or by a logical node, logical module, or software that can implement all or part of the functions of the network device; the method executed by the terminal device in this application embodiment can also be implemented by a communication module in the terminal device or a circuit or chip (such as a modem chip (also known as a baseband chip), or a SoC chip containing a modem core, or a SIP chip) in the terminal device responsible for communication functions.

[0228] like Figure 8 As shown, the flow of this communication method is as follows:

[0229] S801, the network device sends the first information to the terminal device. Correspondingly, the terminal device receives the first information from the network device.

[0230] The first piece of information can be used to determine the M antenna ports and M space layers for transmitting the uplink reference signal.

[0231] The uplink reference signal can be used by network devices to estimate the equivalent channel matrix experienced by the data channel (such as PUSCH) or control channel (such as PUCCH), that is, it can be used by network devices to estimate the equivalent channel (i.e., the aforementioned). For example, the uplink reference signal can be DMRS, SRS, TRS, PTRS, etc., without limitation. For ease of understanding, this application will use DMRS as the uplink reference signal for subsequent description.

[0232] M antenna ports can correspond one-to-one with M space layers, and can be used to carry uplink reference signals. M antenna ports can transmit M data streams, and these M antenna ports correspond one-to-one with M data streams, which can be considered as M space layers.

[0233] For example, taking the DMRS as the reference signal, assume that there are M DMRS ports: port#0, port#1, port#2, ..., port#M-1; and M spatial layers: spatial layer #0, spatial layer #1, spatial layer #2, ..., spatial layer #M-1. For instance, port#0 can correspond to spatial layer #0 (i.e., spatial layer #0 can be used to transmit port#0), port#1 can correspond to spatial layer #1 (i.e., spatial layer #1 can be used to transmit port#1), port#2 can correspond to spatial layer #2 (i.e., spatial layer #2 can be used to transmit port#2), ..., port#M-1 can correspond to spatial layer #M-1 (i.e., spatial layer #M-1 can be used to transmit port#M-1). It is understood that the above correspondence (or association) between the M DMRS ports and the M spatial layers is only an example. The correspondence between the M DMRS ports and the M spatial layers can also be any other possible situation. For example, port #0 can correspond to spatial layer #M-1, port #1 can correspond to spatial layer #M-2, port #2 can correspond to spatial layer #M-3, ..., port #M-1 can correspond to spatial layer #0, etc. This application embodiment does not limit this.

[0234] The M spatial layers can be a subset of the N spatial layers corresponding to the uplink data transmission, used for actually transmitting the uplink reference signal. The N spatial layers corresponding to this uplink data transmission can be the entire set, and the M spatial layers can be a subset of this entire set, where N is greater than M, and N and M are integers greater than 0. For example, for uplink data such as PUSCH, where rank = 4 (i.e., N = 4), and the four spatial layers are spatial layers #0 to #3, then the value of M can be 1, 2, or 3. For example, when M=1, one spatial layer can be any one of spatial layer #0, spatial layer #1, spatial layer #2, or spatial layer #3; when M=2, two spatial layers can be any one of {spatial layer #0, spatial layer #1}, {spatial layer #0, spatial layer #2}, {spatial layer #0, spatial layer #3}, {spatial layer #1, spatial layer #2}, {spatial layer k#1, spatial layer #3}, or {spatial layer #2, spatial layer #3}; when M=3, three spatial layers can be any one of {spatial layer #0, spatial layer #1, spatial layer #2}, {spatial layer #0, spatial layer #1, spatial layer #3}, {spatial layer #0, spatial layer #2, spatial layer #3}, {spatial layer #1, spatial layer #2, spatial layer #3}. It can be understood that the value of N is not greater than (i.e. less than or equal to) the maximum number of antennas that the terminal device has, or in other words, the value of N is not greater than the maximum number of spatial layers supported by the terminal device.

[0235] The following example illustrates the first piece of information.

[0236] Case 1: The first information includes the first instruction information and the second instruction information.

[0237] The first indication information can be used to indicate N space layers and N antenna ports corresponding one-to-one with the N space layers. The second indication information can be used to indicate M space layers, that is, the second indication information can indicate the M space layers that actually transmit uplink reference signals among the N space layers.

[0238] The following section provides a detailed explanation of how the first instruction information is used to indicate N spatial layers.

[0239] For example, the first indication information can specifically be used to indicate that the number of spatial layers corresponding to the uplink data transmission is N. These N spatial layers are arranged in a predefined manner. The terminal device can determine the N spatial layers based on the number N spatial layers indicated by the first indication information and the predefined arrangement. It is understood that the first indication information can also indicate the N spatial layers in any other possible form. For example, the first indication information can directly indicate the index of the N spatial layers. In this case, the terminal device can directly determine the N spatial layers based on the first indication information. This application embodiment does not limit this.

[0240] The first indication information is described in detail below, which indicates the N antenna ports that correspond one-to-one with the N space layers.

[0241] It is understood that, based on the above description of the one-to-one correspondence between M antenna ports and M space layers, the one-to-one correspondence between N space layers and N antenna ports is also applicable and will not be elaborated further. The M antenna ports can be a subset of the N antenna ports used for actually transmitting uplink reference signals. For example, the first indication information can specifically indicate the indices of the N antenna ports, and the terminal device can determine the N antenna ports based on the antenna port indices indicated by the first indication information. It is understood that the first indication information can also indicate the N antenna ports in any other possible form, and this application embodiment does not limit this.

[0242] The following example illustrates the representation of the second instruction information.

[0243] Method 1: The second indication information is represented by a bitmap.

[0244] Among them, the value of each bit in the bitmap is used to indicate whether one of the N spatial layers sends an uplink reference signal. That is, the bit length occupied by the bitmap can be N, and these N bits can correspond to the N spatial layers one by one. Exemplarily, the nth bit among the N bits corresponds to the nth spatial layer among the N spatial layers, where 0 < n ≤ N. When the value of the nth bit is 1, it can indicate that the nth spatial layer is used to send an uplink reference signal; when the value of the nth bit is 0, it can indicate that the nth spatial layer does not send an uplink reference signal; or when the value of the nth bit is 0, it can indicate that the nth spatial layer is used to send an uplink reference signal, and when the value of the nth bit is 1, it can indicate that the nth spatial layer does not send an uplink reference signal, which is not limited. For ease of understanding, in the embodiments of this application, an example where the value of the bit in the bitmap is 1, indicating that the corresponding spatial layer is used to send an uplink reference signal, is used for subsequent introduction.

[0245] Exemplarily, as Figure 9 shown, taking the terminal device having 8 transmit antennas and supporting a maximum rank = 8 (N = 8) as an example, these 8 transmit antennas can be port #0 - port #7 (i.e., port#0 - port#7), and these 8 spatial layers can be spatial layer #0 - spatial layer #7. port#0 - port#7 and spatial layer #0 - spatial layer #7 can correspond to each other one by one. For example, port#0 can correspond to spatial layer #0, port#1 can correspond to spatial layer #1, port#2 can correspond to spatial layer #2, port#3 can correspond to spatial layer #3, port#4 can correspond to spatial layer #4, port#5 can correspond to spatial layer #5, port#6 can correspond to spatial layer #6, and port#7 can correspond to spatial layer #7.

[0246] Assume that the 8-bit bitmap indicates spatial layer #0 - spatial layer #7 in sequence from the low-order bit to the high-order bit / from left to right. For example, if the value of the 8-bit bitmap of the second indication information is "11001100", it can indicate that the 4 spatial layers (i.e., M = 4) actually sending uplink reference signals among spatial layer #0 - spatial layer #7 are spatial layer #0, spatial layer #1, spatial layer #4, and spatial layer #5.

[0247] It can be understood that the network device can obtain the channel correlation between each antenna through other uplink reference signals, such as SRS, and can better determine which spatial layers are used for measurement or interpolation with better performance. Based on Method 1, the network device can more flexibly select the spatial layers for sending uplink reference signals, thereby providing the network device with sufficient freedom to best adapt to the channel conditions, and can select the best spatial layers for measurement to obtain the best performance.

[0248] Method 2: The second indication information is represented by bit state indication information.

[0249] The bit state indication information may include different bit states, which can be represented by different bit values. Different values ​​can represent different spatial layer combinations (or sets of spatial layers). The spatial layer combination may contain one or more spatial layers from the aforementioned N spatial layers, and each spatial layer combination may contain fewer than N spatial layers. The terminal device can indicate a bit value through the bit state indication information, and the terminal device can determine a spatial layer combination based on the association between the bit value and the spatial layer combination. The spatial layers in a spatial layer combination may be the aforementioned M spatial layers. It is understood that the bit length occupied by the bit state indication information may be related to the number of different spatial layer combinations corresponding to the N spatial layers, and this embodiment of the application does not limit this.

[0250] For example, consider a terminal device with four transmit antennas, supporting a maximum rank of 4 (N=4). These four transmit antennas can be ports #0 to #3 (i.e., port#0-port#3), and the four spatial layers can be spatial layers #0 to #3. Ports #0 to #3 can correspond one-to-one with spatial layers #0 to #3; for example, port#0 can correspond to spatial layer #1, port#1 to spatial layer #1, port#2 to spatial layer #2, and port#3 to spatial layer #3. These four spatial layers can correspond to 14 spatial layer combinations, thus requiring four bits for the bit status indication information.

[0251] A possible mapping relationship between bit states and spatial layer combinations is shown in Table 13. For example, if the bit field value of the bit state indication information is "0000", then the spatial layer combination can be spatial layer #0; if the bit field value of the bit state indication information is "0001", then the spatial layer combination can be spatial layer #1; if the bit field value of the bit state indication information is "0010", then the spatial layer combination can be spatial layer #2; if the bit field value of the bit state indication information is "0011", then the spatial layer combination can be spatial layer #3; if the bit field value of the bit state indication information is "0100", then the spatial layer combination can be {spatial layer #0, spatial layer #1}; if the bit field value of the bit state indication information is "0101", then the spatial layer combination can be {spatial layer #0, spatial layer #2}; if the bit field value of the bit state indication information is "0110", then the spatial layer combination can be { If the bit field value of the bit status indication information is "0111", then the spatial layer combination can be {spatial layer #1, spatial layer #2}; if the bit field value of the bit status indication information is "1000", then the spatial layer combination can be {spatial layer #2, spatial layer #3}; if the bit field value of the bit status indication information is "1010", then the spatial layer combination can be {spatial layer #0, spatial layer #1, spatial layer #2}; if the bit field value of the bit status indication information is "1011", then the spatial layer combination can be {spatial layer #0, spatial layer #1, spatial layer #3}; if the bit field value of the bit status indication information is "1100", then the spatial layer combination can be {spatial layer #0, spatial layer #2, spatial layer #3}; if the bit field value of the bit status indication information is "1101", then the spatial layer combination can be {spatial layer #1, spatial layer #2, spatial layer #3}. It is understandable that, given the predefined or preconfigured number of actual transmitting antenna ports (i.e., the predefined or configured value of M), a possible mapping relationship between bit states and spatial layer combinations could be part of Table 13. For example, when M = 3, the mapping relationship between bit states and spatial layer combinations is only the last 4 rows in Table 13 (the corresponding bit field values ​​of the bit state indication information are “1010”, “1011”, “1100”, and “1101”).

[0252] Table 13

[0253] Bit state Spatial layer combination (N=8, spatial layer #0-spatial layer #7) 0000 Space layer #0 0001 Space layer #1 0010 Space layer #2 0011 Space layer #3 0100 Space layer k#0, Space layer #1 0101 Space layer #0, Space layer #2 0110 Space layer #0, Space layer #3 0111 Space layer #1, Space layer #2 1000 Space layer #1, Space layer #3 1001 Space layer #2, Space layer #3 1010 Space layer #0, Space layer #1, Space layer #2 1011 Space layer #0, Space layer #1, Space layer #3 1100 Space layer #0, Space layer #2, Space layer #3 1101 Space layer #1, Space layer #2, Space layer #3

[0254] Assuming the bit state indicated by the second indication information is "1010", it means that the three spatial layers (i.e., M=3) that actually transmit the uplink reference signal in spatial layers #0 to #3 are spatial layer #0, spatial layer #1, and spatial layer #2. These spatial layers #0, #1, and #2 correspond one-to-one with port #0, port #1, and port #2, respectively. It is understood that Table 13 is merely an example; the mapping relationship between bit states and spatial layer combinations can be any other possible relationship, without limitation.

[0255] It is understood that the above methods 1 and 2 are merely examples, and the second instruction information can also be represented in any other possible form without limitation.

[0256] Scenario 2: The first information includes the first instruction information and the second instruction information.

[0257] The first indication information can be used to indicate N space layers and M antenna ports. The second indication information can be used to indicate M space layers.

[0258] It is understood that the first indication information is used to provide a detailed description of the N space layers, which can be referred to in the relevant description in Case 1 above, and will not be repeated here. The following is a detailed description of the first indication information indicating the M antenna ports.

[0259] For example, the first indication information may specifically indicate M antenna port indices, and the terminal device can determine the M antenna ports based on the antenna port indices indicated by the first indication information. It is understood that the first indication information may also indicate the M antenna ports in any other possible form, and this application embodiment does not limit this.

[0260] The second indication information can be represented by a bitmap. The value of each bit in the bitmap can indicate whether one of the N spatial layers has sent an uplink reference signal; for details, please refer to the relevant content in Method 1 above, which will not be repeated here. Alternatively, the second indication information can be represented by bit state indication information; for details, please refer to the relevant content in Method 2 above, which will not be repeated here. It is understood that the second indication information can also be represented in any other possible form, without limitation.

[0261] Based on situations 1 and 2 above, in one possible design scheme, the above method further includes:

[0262] The terminal device determines M antenna ports and M space layers based on the first and second indication information.

[0263] In other words, the terminal device can determine M antenna ports and M spatial layers based on the combined indication of the first and second indication information. It can be understood that in Case 1 above, the first indication information follows the existing NR protocol's method of indicating antenna port index combinations, and further establishes the association between the first and second indication information. Thus, the terminal device can determine the M antenna ports based on the M spatial layers indicated by the second indication information. In Case 2 above, the terminal device can re-indicate the antenna port combination in the antenna port combination table corresponding to a lower spatial layer number based on the actual number of spatial layers of the transmitting antenna ports. This can better ensure that the actual transmitting antenna ports have optimal performance or minimal resource consumption. For a detailed explanation, please refer to the relevant content in Examples 1 and 2 below; it will not be repeated here.

[0264] Case 3: The first information is used to indicate N space layers and N antenna ports corresponding one-to-one with the N space layers.

[0265] In scenario 3, the first information can be the first instruction information in scenario 1 above. For a detailed description, please refer to the relevant description in scenario 1 above, which will not be repeated here.

[0266] Case 4: The first information is used to indicate N space layers and M antenna ports.

[0267] In scenario 4, the first information can be the first instruction information in scenario 2 above. For a detailed description, please refer to the relevant description in scenario 2 above, which will not be repeated here.

[0268] Based on scenarios 3 and 4, one possible design scheme also includes the following:

[0269] The terminal device determines M antenna ports and M space layers based on the first information and the pre-configuration information.

[0270] The pre-configuration information can be used to indicate M spatial layers. That is, the M spatial layers used to transmit the uplink reference signal can be pre-configured or pre-defined. The indices of the pre-configured or pre-defined M spatial layers can be multiple equally spaced index values, or can include multiple consecutive index groups with the same index value interval between adjacent index groups, etc. This application embodiment does not limit this.

[0271] For example, continuing with the example of a terminal device having 8 transmit antennas, supporting a maximum rank of 8 (N=8), these 8 transmit antennas can be ports #0 to #7 (i.e., port #0 to port #7), and these 8 spatial layers can be spatial layers #0 to #7. Ports #0 to #7 can correspond one-to-one with spatial layers #0 to #7. For example, port #0 can correspond to spatial layer #0, port #1 can correspond to spatial layer #1, port #2 can correspond to spatial layer #2, port #3 can correspond to spatial layer #3, port #4 can correspond to spatial layer #4, port #5 can correspond to spatial layer #5, port #6 can correspond to spatial layer #6, and port #7 can correspond to spatial layer #7.

[0272] For example, the indices of the M spatial layers can be multiple index values ​​with equal intervals. For instance, when the interval is 1, the spatial layers used to transmit the uplink reference signal can be spatial layer #0, spatial layer #2, spatial layer #4, and spatial layer #6; when the equal interval between spatial layers is 2, the spatial layers used to transmit the uplink reference signal can be spatial layer #0, spatial layer #3, and spatial layer #6; when the interval is 3, the spatial layers used to transmit the uplink reference signal can be spatial layer #0, spatial layer #3, and spatial layer #6; ...; and so on, without further elaboration.

[0273] For example, the indexes of M spatial layers can include multiple index groups with consecutive index values, and the index value interval between adjacent index groups is the same. For instance, assuming each index group contains 2 spatial layers and the index value interval between adjacent index groups is 2, the spatial layers used to transmit uplink reference signals could be (Spatial Layer #0, Spatial Layer #1) and (Spatial Layer #4, Spatial Layer #5), where (Spatial Layer #0, Spatial Layer #1) can be the first group of spatial layers, and (Spatial Layer #4, Spatial Layer #5) can be the second group of spatial layers. Alternatively, assuming each index group corresponds to 1 spatial layer and the index value interval between adjacent index groups is 3, the spatial layers used to transmit uplink reference signals could be spatial layer #0, spatial layer #4, and spatial layer #7, where spatial layer #0 can be the first group of spatial layers, spatial layer #4 can be the second group of spatial layers, and spatial layer #7 can be the third group of spatial layers. It is understood that the above are merely examples, and pre-configuration information can be represented in any other possible form without limitation.

[0274] Based on scenarios 3 and 4, the terminal device can determine the M antenna ports and M spatial layers according to the first information and the pre-configuration information. Compared with scenarios 1 and 2 above, the network device does not need additional signaling to indicate the actual spatial layers transmitting the uplink reference signal, i.e., the M spatial layers, thus saving indication overhead.

[0275] The following example, using the DMRS as the upper reference signal, will be used to specifically introduce cases 1 and 2 above.

[0276] Example 1 (corresponding to Case 1 above): The first indication information indicates that the number of spatial layers corresponding to PUSCH is 8, and the DMRS port index is 0-7. That is, the number of DMRS port indices indicated by the first indication information is equal to the number of spatial layers corresponding to PUSCH. The second indication information indicates that the spatial layers corresponding to the DMRS actually sent are spatial layer #0, spatial layer #2, spatial layer #4, and spatial layer #6.

[0277] The eight spatial layers can be spatial layers #0 to #7 (i.e., spatial layers #0 to #7), arranged in a predefined manner. Spatial layers #0 to #7 can thus represent the aforementioned N spatial layers, where N = 8. The DMRS port indices 0-7 can correspond to DMRS ports #0 to #7, which can also represent the aforementioned N antenna ports. Spatial layers #0 to #7 correspond one-to-one with ports #0 to #7. For example, port #0 can correspond to spatial layer #0, port #1 to spatial layer #1, port #2 to spatial layer #2, port #3 to spatial layer #3, port #4 to spatial layer #4, port #5 to spatial layer #5, port #6 to spatial layer #6, and port #7 to spatial layer #7. Spatial layers #0, #2, #4, and #6 can thus represent the aforementioned M spatial layers. Terminal devices can send port #0 through spatial layer #0, port #2 through spatial layer #2, port #4 through spatial layer #4, and port #6 through spatial layer #6.

[0278] When rank=8 and DMRS port index is 0-7, as shown in Table 14 below, the terminal device needs to occupy 2 symbols to transmit DMRS. The terminal device can determine, based on the first and second indication information, to transmit DMRS on a portion of the spatial layers #0-#7 and a portion of the ports #0-#7. That is, the terminal device can transmit DMRS on port #0 via spatial layer #0, on port #2 via spatial layer #2, on port #4 via spatial layer #4, and on port #6 via spatial layer #6. For example... Figure 9As shown, if all eight spatial layers transmit DMRS ports, DMRS would require all subcarriers within two symbols. However, based on Example 1, the terminal device only needs to transmit DMRS on ports #0, #2, #4, and #6. Thus, DMRS can occupy only half of the subcarriers within two symbols. Therefore, the frequency domain resource overhead of DMRS can be reduced by half, allowing the saved subcarriers to be mapped to other users' DMRS resources or used for transmitting uplink data, such as PUSCH.

[0279] Table 14

[0280]

[0281] Example 2 (corresponding to Case 2 above): The first indication information indicates that the number of spatial layers corresponding to PUSCH is 8, and the DMRS port index is 0-3. That is, the number of DMRS port indices indicated by the first indication information is equal to the actual number of DMRS ports used to send DMRS. In other words, the number of DMRS port indices indicated by the first indication information is less than the number of spatial layers corresponding to PUSCH. The second indication information indicates that the spatial layers corresponding to the actual DMRS sent are spatial layer #0, spatial layer #2, spatial layer #4, and spatial layer #6.

[0282] The eight spatial layers can be spatial layers #0 to #7 (i.e., spatial layers #0 to #7), arranged in a predefined manner. Spatial layers #0 to #7 can represent the aforementioned N spatial layers, where N = 8. Each spatial layer #0 to #7 can correspond one-to-one with port #0 to port #7, which can represent the aforementioned N antenna ports. The DMRS port indices 0-3 can correspond to DMRS ports #0 to #3, which can represent the aforementioned M antenna ports, where M = 4.

[0283] When rank = 4 and DMRS port index is 0-3, as shown in Table 10 above, the terminal device only needs to occupy 1 symbol to send DMRS. The terminal device can determine, based on the first and second indication information, to send DMRS on a portion of the spatial layers #0-#7 and a portion of the ports #0-#7. That is, the terminal device can send DMRS on port #0 via spatial layer #0, on port #1 via spatial layer #2, on port #2 via spatial layer #4, and on port #3 via spatial layer #6. For example... Figure 10As shown, if all eight spatial layers transmit DMRS ports, DMRS would require occupying all subcarriers in two symbols. However, based on Example 2, the terminal device only needs to transmit DMRS on port#0, port#1, port#2, and port#3, thus DMRS can occupy only one symbol. Therefore, the time-domain resource overhead of DMRS can be reduced by half, allowing the saved subcarriers to be mapped to other users' DMRS resources or used to transmit uplink data, such as PUSCH.

[0284] It is understandable that the specific implementation of the above situations 3 and 4 is similar to that of the above examples 1 and 2. The difference lies in the content indicated by the second indication information in the above examples 1 and 2, that is, the spatial layer of the actual DMRS being sent is pre-configured or pre-defined. The implementation principle is similar and can be understood by reference, without going into details.

[0285] It should be understood that in cases 1 and 2 above, the network device indicates to the terminal device, through the second indication information, the M spatial layers out of the N spatial layers that transmit uplink reference signals. The second indication information can also indicate spatial layers out of the N spatial layers that do not transmit uplink reference signals, such as K spatial layers out of the N spatial layers, where N is greater than K and K is an integer greater than 0. When the second indication information indicates NM spatial layers out of the N spatial layers that do not transmit uplink reference signals, the terminal device can determine the M spatial layers out of the N spatial layers that transmit uplink reference signals based on the N spatial layers indicated by the first indication information and the NM spatial layers indicated by the second indication information. In cases 3 and 4 above, the pre-configuration information can indicate M spatial layers out of N spatial layers that transmit uplink reference signals. Similarly, the pre-configuration information can also indicate NM spatial layers out of N spatial layers that do not transmit uplink reference signals. The terminal device can determine the M spatial layers out of N spatial layers that transmit uplink reference signals based on the N spatial layers indicated by the first indication information and the NM spatial layers indicated by the pre-configuration information. This application embodiment does not limit this.

[0286] Case 5: The first information is used to indicate the first antenna port combination corresponding to N space layers, and the antenna ports in the first antenna port combination are M antenna ports.

[0287] In this system, N spatial layers correspond one-to-one with N antenna ports. Based on the previous explanation of the one-to-one correspondence between M antenna ports and M spatial layers, the correspondence between N spatial layers and N antenna ports is also straightforward and will not be elaborated further. The N antenna ports are associated with L combinations of antenna ports. These N antenna ports can be a first-type antenna port combination (set), which can contain one or more antenna port combinations. The number of antenna ports in each first-type antenna port combination can be equal to the number of spatial layers N corresponding to the uplink data transmission. The L antenna port combinations can be a second-type antenna port combination (set), where each antenna port combination in the L combinations can contain one or more of the N antenna ports. The number of antenna ports in each of the L combinations is less than the number of spatial layers N corresponding to the uplink data transmission. The first antenna port combination can be one of the L antenna port combinations, where L is a positive integer.

[0288] The first indication information can specifically indicate the index of the first antenna port combination, that is, indicate the first antenna port index combination. In this way, the terminal device can determine the first antenna port combination based on the first information. It is understood that the first indication information can also indicate the first antenna port combination corresponding to N space layers in any other possible form, and the embodiments of this application do not limit this.

[0289] N antenna ports can correspond to the same spatial layer as antenna ports with the same antenna port index in the first type of antenna port combination. That is, the first type of antenna port combination is associated with the second type of antenna port combination. For example, an antenna port combination in the first type of DMRS port combination (such as antenna port combination #a) is associated with an antenna port combination in the second type of DMRS port combination (such as antenna port combination #b). The antenna port indexes in antenna port combination #a and antenna port combination #b can correspond to the same spatial layer, or in other words, the antenna ports with the same antenna port indexes in antenna port combination #a and antenna port combination #b can correspond to the same spatial layer.

[0290] For example, taking the uplink reference signal as DMRS, when the rank value corresponding to uplink data transmission is high, the number of supported optional DMRS port combinations is small, resulting in a large number of redundant status bits in the corresponding DMRS port combination table. Taking the optional DMRS port combination corresponding to type 1 single-symbol DMRS with a rank value of 3 as an example, as shown in Table 5 above, the defined optional DMRS port combination has only one unique DMRS port combination. That is, the DMRS port corresponding to the indication information value of 0 can be port#0-por#2, while the DMRS port indication information values ​​of 1-7 can all be redundant status bits.

[0291] Taking type 1 double-symbol DMRS with a rank value of 3 as an example, as shown in Table 9 above, there are 3 sets of optional DMRS port combinations. For example, the DMRS ports corresponding to an indication value of 0 can be port#0-port#2; the DMRS ports corresponding to an indication value of 1 can be port#0, port#1, and port#4; and the DMRS ports corresponding to an indication value of 2 can be port#2, port#3, and port#6. Indication values ​​from 3 to 15 can all be redundant status bits.

[0292] It is understood that the above is an introduction to the optional DMRS port combinations with a rank value of 3 as an example. If the rank value is other values, such as rank values ​​of 4, 5, 6, 7, 8, etc., the corresponding DMRS port table also has similar redundant status bits. For details, please refer to the existing technology, which will not be elaborated here.

[0293] Therefore, based on Tables 5 and 9 above, new antenna port combinations can be carried using the redundant status bits in the antenna port tables. The following example illustrates how to carry new DMRS port combinations using the redundant status bits in Tables 5 and 9.

[0294] Implementation 1: Type 1 single-symbol DMRS, with a rank value of 3 corresponding to the optional DMRS port combination.

[0295] In Implementation 1, based on the redundant status bits in Table 5 above, the defined DMRS port combination table can be as shown in Table 15. Table 15 can include two types of DMRS port combinations. The first type of DMRS port combination can contain one DMRS port combination, that is, the corresponding DMRS ports corresponding to the indication information value of 0 are port#0-port#2. These port#0-port#2 can correspond one-to-one with spatial layers #0-#2. For example, port#0 can correspond to spatial layer #0, port#1 can correspond to spatial layer #1, and port#2 can correspond to spatial layer #2.

[0296] The second type of DMRS port combination can contain three DMRS port combinations (indication information values ​​1-3). Specifically, an indication information value of 1 corresponds to DMRS ports #0 and #1, an indication information value of 2 corresponds to DMRS ports #0 and #2, and an indication information value of 3 corresponds to DMRS ports #1 and #2. Each of these three DMRS port combinations can contain two DMRS ports, indicating that the actual number of DMRS ports transmitting is two. Antenna ports with the same antenna port index in the DMRS port combinations with indication information values ​​1-3 and the DMRS port combination with indication information value 0 can correspond to the same space layer. It can be understood that in Table 15, indication information values ​​4-7 can still be reserved.

[0297] Table 15

[0298]

[0299] The network device can send first information to the terminal device, indicating a value in the first column of the optional DMRS port combination table (i.e., Table 15) corresponding to the three spatial layers. This value corresponds to a row in the optional DMRS port combination table. For example, assuming the first information indicates a value of 2, the terminal device can determine, based on the value of 2 and Table 15, to send DMRS on spatial layers #0 and #2 via port #0 and port #2, respectively. That is, the terminal device can send DMRS on spatial layer #0 via port #0 and on spatial layer #2 via port #2. The terminal device does not need to send DMRS on spatial layer #1 (corresponding to port #1).

[0300] Implementation 2: Type 1 double-symbol DMRS, with a rank value of 3 corresponding to the optional DMRS port combination.

[0301] In Implementation 2, based on the redundant status bits in Table 9 above, the defined DMRS port combination table can be as shown in Table 16. Table 16 can include two types of DMRS port combinations. The first type of DMRS port combination can include three DMRS port combinations, that is, three DMRS port combinations corresponding to indication information values ​​of 0, 4, and 8 respectively. Specifically, the DMRS ports corresponding to indication information value of 0 can be port#0-port#2; the DMRS ports corresponding to indication information value of 4 can be port#0, port#1, and port#4; and the DMRS ports corresponding to indication information value of 8 can be port#2, port#3, and port#6.

[0302] The second type of DMRS port combination can include 9 DMRS port combinations (indication information values ​​are 1-3, 5-7, 9-11). That is, the DMRS ports corresponding to the indication information value of 1 can be port#0 and port#1; the DMRS ports corresponding to the indication information value of 2 can be port#0 and port#2; the DMRS ports corresponding to the indication information value of 3 can be port#1 and port#2; the DMRS ports corresponding to the indication information value of 5 can be port#0 and port#1; the DMRS ports corresponding to the indication information value of 6 can be port#0 and port#4; the DMRS ports corresponding to the indication information value of 7 can be port#1 and port#4; the DMRS ports corresponding to the indication information value of 9 can be port#2 and port#3; the DMRS ports corresponding to the indication information value of 10 can be port#2 and port#6; and the DMRS ports corresponding to the indication information value of 11 can be port#3 and port#6. Each of the nine DMRS port combinations can contain two DMRS ports, indicating that the actual number of DMRS ports used for transmission is two.

[0303] Antenna ports with the same antenna port index in the DMRS port combination corresponding to indication information values ​​of 1-3 and the DMRS port combination corresponding to indication information value of 0 can correspond to the same space layer; antenna ports with the same antenna port index in the DMRS port combination corresponding to indication information values ​​of 5-7 and the DMRS port combination corresponding to indication information value of 4 can correspond to the same space layer; antenna ports with the same antenna port index in the DMRS port combination corresponding to indication information value of 9-11 and the DMRS port combination corresponding to indication information value of 8 can correspond to the same space layer. It can be understood that in Table 16, indication information values ​​of 12-15 can still be reserved.

[0304] Table 16

[0305]

[0306] The network device can send first information to the terminal device, indicating a value in the first column of the optional DMRS port combination table (i.e., Table 16) corresponding to the three spatial layers. This value corresponds to a row in the optional DMRS port combination table. For example, assuming a one-to-one correspondence between port #0-port #2 and spatial layers #0-#2 (i.e., port #0 corresponds to spatial layer #0, port #1 corresponds to spatial layer #1, and port #2 corresponds to spatial layer #2), and assuming the first information indicates a value of 3, the terminal device can determine, based on the value of 3 and Table 16, to send DMRS through ports #1 and #2 in spatial layers #0-#2. That is, the terminal device can send DMRS through port #1 in spatial layer #1 and through port #2 in spatial layer #2. The terminal device does not need to send DMRS in spatial layer #0 (corresponding to port #0).

[0307] It is understood that Implementation 1 and Implementation 2 described above are based on the example of N=3 and M=2, and are merely illustrative. When N and M are other possible values, the corresponding optional DMRS port combination table is similar to Tables 15 and 16 above, which can be used for reference and understanding, and will not be elaborated upon further.

[0308] Based on scenario 5, new antenna port combinations are added to the predefined or preconfigured optional antenna port combination tables (such as Tables 15 and 16 above). These newly added antenna port combinations can be used to indicate which space layer antenna ports are being transmitted. Specifically, the number of antenna ports included in the newly added antenna port combinations (i.e., the second type of antenna port combinations mentioned above) is less than the number of space layers corresponding to uplink data transmission, and it is associated with the original antenna port combinations (i.e., the first type of antenna port combinations mentioned above). Therefore, by utilizing the redundant status bits in the current antenna port combination table, it is possible to implicitly indicate which space layers transmit which antenna ports' corresponding uplink reference signal resources. In this way, M space layers and M antenna ports can be implicitly indicated without increasing overhead, effectively reducing indication overhead, such as the indication overhead of DCI signaling.

[0309] Based on the above description, in one possible design scheme, the first information can be used to indicate the uplink precoding matrix. For example, assuming rank = 4, the first information can indicate the TPMI index. The terminal device can determine the precoding matrix from the codebook shown in Table 12 based on the TPMI. This precoding matrix is ​​the precoding matrix configured by the network device for uplink transmission. It is understood that the first information, used to indicate the uplink precoding matrix, can also be represented in any other possible form without limitation.

[0310] It is understood that the aforementioned first information can be carried in existing information cells to reduce implementation difficulty, such as RRC signaling, DCI, MAC-CE signaling, system information block (SIB) 1, etc., or it can be carried in new information cells to improve implementation flexibility, without limitation. The naming of the aforementioned first information, first indication information, and second indication information is only an example, and the first information, first indication information, and second indication information can also be replaced with any other possible names, without limitation.

[0311] S802, the terminal device transmits a first uplink reference signal through M antenna ports on M spatial layers according to the first information. Correspondingly, the network device receives the first uplink reference signal from the terminal device.

[0312] That is, the first uplink reference signal can be transmitted through M antenna ports on M spatial layers. It can be understood that, combining the above situations 1-5, the terminal device can determine the M antenna ports and M spatial layers for transmitting the uplink reference signal based on the first information, and transmit the first uplink reference signal through the M antenna ports on the determined M spatial layers.

[0313] For example, taking cases 1 and 2 above as examples, assume the first uplink reference signal is DMRS#1. In case 1 above, as Figure 9 As shown, the terminal device can transmit DMRS#1 on port#0 via spatial layer #0, DMRS#1 on port#2 via spatial layer #2, DMRS#1 on port#4 via spatial layer #4, and MRS#1 on port#6 via spatial layer #6; in case 2 above, as Figure 10 As shown, the terminal device can send MRS#1 on port#0 via spatial layer #0, MRS#1 on port#1 via spatial layer #2, DMRS#1 on port#2 via spatial layer #4, and DMRS#1 on port#3 via spatial layer #6.

[0314] In one possible design, the terminal device, based on the first information, transmits a first uplink reference signal through M antenna ports on M spatial layers, including:

[0315] The terminal device transmits the first uplink reference signal through M antenna ports on M spatial layers according to the uplink precoding matrix.

[0316] That is, the first information can be used to indicate the uplink precoding matrix, and the first uplink reference signal can be determined based on the uplink precoding matrix. The terminal device can use the uplink precoding matrix determined by the first information to precode the first uplink reference signal to ensure uplink transmission performance. For specific implementation, please refer to existing implementations, which will not be elaborated here.

[0317] In summary, based on the received first information, the terminal device can determine the M antenna ports and M spatial layers for actually transmitting the uplink reference signal. These M spatial layers are a subset of the N spatial layers corresponding to uplink data transmission, and the M antenna ports correspond one-to-one with the M spatial layers. Thus, the terminal device can transmit the uplink reference signal through the M antenna ports only on a subset of the N spatial layers corresponding to uplink data transmission, i.e., the M spatial layers, as described above as the first uplink reference signal. This effectively reduces the resource overhead of the uplink reference signal. When the number of spatial layers corresponding to uplink data transmission increases exponentially, the resource overhead of the uplink reference signal can be effectively controlled, allowing the saved resources to be used for data transmission or for transmitting uplink reference signals for other users. Within the limited resource constraints (such as time-frequency resources), this effectively improves resource utilization efficiency, network capacity, and user experience.

[0318] The above combination Figures 8-10 The communication method provided in the embodiments of this application is described in detail below. Figures 11-12 This document describes in detail the communication apparatus used to perform the communication method provided in the embodiments of this application.

[0319] Figure 11 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Figure 1 For example, such as Figure 11 As shown, the communication device 1100 includes a transceiver module 1101 and a processing module 1102. For ease of explanation, Figure 11 Only the main components of the communication device 1100 are shown.

[0320] The transceiver module 1101 is used to perform the above-mentioned tasks. Figure 8 The sending and receiving functions of the method shown are executed by the processing module 1102. Figure 8 The method shown includes functions other than sending and receiving.

[0321] Optionally, the transceiver module 1101 may include a transmitting module ( Figure 11 (not shown in the image) and receiving module ( Figure 11 (Not shown in the diagram). The transmitting module is used to implement the transmitting function of the communication device 1100, and the receiving module is used to implement the receiving function of the communication device 1100.

[0322] For example, a transceiver module is used to receive first information and, based on the first information, transmit a first uplink reference signal through M antenna ports on M spatial layers. The first information is used to determine the M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers. The M spatial layers are a subset of the N spatial layers corresponding to the uplink data transmission, where N and M are integers greater than 0. A processing module is used to determine the M antenna ports and M spatial layers based on the first information and pre-configuration information. The pre-configuration information indicates the M spatial layers.

[0323] The processing module controls the transceiver module to send the first information. The transceiver module receives the first uplink reference signal. The first information determines the M antenna ports and M spatial layers for transmitting the uplink reference signal, with each of the M antenna ports corresponding to one of the M spatial layers. The M spatial layers are a subset of the N spatial layers corresponding to the uplink data transmission, where N and M are integers greater than 0. The first uplink reference signal is transmitted through the M antenna ports on the M spatial layers.

[0324] Optionally, the communication device 1100 may also include a storage module. Figure 11 (Not shown in the image), the storage module stores programs or instructions. When the processing module 1102 executes the program or instructions, the communication device 1100 can perform the above-described method. Figure 8 The methods shown describe the functions of the terminal devices and / or network devices.

[0325] It is understood that the communication device 1100 may be a terminal device, or a chip (system) or other component or assembly that can be disposed in a terminal device, or a device that includes a terminal device; or, the communication device 1100 may be a network device, or a chip (system) or other component or assembly that can be disposed in a network device, or a device that includes a network device. The embodiments of this application do not limit this.

[0326] In addition, the technical effects of the communication device 1100 can be referenced. Figure 8 The technical effects of the communication method shown will not be elaborated here.

[0327] For example, Figure 12 Schematic diagram of the communication device provided in the embodiments of this application Figure 2The communication device can be a terminal device or a network device, or it can be a chip (system) or other component or assembly of the terminal device or network device. For example... Figure 12 As shown, the communication device 1200 may include a processor 1201. Optionally, the communication device 1200 may also include a memory 1202 and / or a transceiver 1203. The processor 1201 is coupled to the memory 1202 and the transceiver 1203, for example, they may be connected via a communication bus.

[0328] The following is combined with Figure 12 A detailed description of each component of the communication device 1200 is provided below:

[0329] The processor 1201 is the control center of the communication device 1200. It can be a single processor or a collective term for multiple processing elements. For example, the processor 1201 can be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0330] Optionally, the processor 1201 can perform various functions of the communication device 1200, such as the functions described above, by running or executing software programs stored in the memory 1202 and calling data stored in the memory 1202. Figure 8 or Figure 10 The communication method shown.

[0331] In a specific implementation, as one example, the processor 1201 may include one or more CPUs, for example... Figure 12 CPU0 and CPU1 are shown in the diagram.

[0332] In a specific implementation, as one example, the communication device 1200 may also include multiple processors, for example... Figure 12 The processors 1201 and 1204 are shown. Each of these processors can be a single-core processor (CPU) or a multi-core processor (CPU). Here, "processor" can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0333] For example, taking processor 1201 as an example, processor 1201 may include communication and processing circuitry. The communication and processing circuitry may include one or more hardware components that provide a physical structure that performs various processes related to wireless communication (e.g., signal reception and / or signal transmission). The communication and processing circuitry may include two or more transmit / receive chains. The functions implemented by the communication and processing circuitry may also be processed on a computer-readable medium.

[0334] Processor 1201 can execute the above steps S801 and S802, that is, processor 1201 can receive first information and, based on the first information, transmit a first uplink reference signal through M antenna ports on M spatial layers. The first information can be used to determine the M antenna ports and M spatial layers for transmitting the uplink reference signal; the M antenna ports can correspond one-to-one with the M spatial layers; the M spatial layers can be some of the N spatial layers corresponding to the uplink data transmission, and N and M can be integers greater than 0.

[0335] The memory 1202 is used to store the software program that executes the solution of this application, and is controlled by the processor 1201 to execute it. The specific implementation method can be referred to the above method embodiment, and will not be repeated here.

[0336] Optionally, the memory 1202 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 1202 may be integrated with the processor 1201 or exist independently, and may be connected via the interface circuit of the communication device 1200. Figure 12 (Not shown in the image) is coupled to the processor 1201, and this embodiment does not specifically limit this.

[0337] Transceiver 1203 is used for communication with other communication devices. For example, if communication device 1200 is a terminal device, transceiver 1203 can be used to communicate with a network device or with another terminal device. As another example, if communication device 1200 is a network device, transceiver 1203 can be used to communicate with a terminal device or with another network device.

[0338] Optionally, transceiver 1203 may include a receiver and a transmitter. Figure 12 (Not shown separately). The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function.

[0339] Optionally, the transceiver 1203 can be integrated with the processor 1201, or it can exist independently and be connected via the interface circuit of the communication device 1200. Figure 12 (Not shown in the image) is coupled to the processor 1201, and this embodiment does not specifically limit this.

[0340] It should be noted that, Figure 12 The structure of the communication device 1200 shown does not constitute a limitation on the communication device. Actual communication devices may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0341] Furthermore, the technical effects of the communication device 1200 can be referenced from the above. Figure 8 The technical effects of the communication method shown will not be elaborated here.

[0342] This application provides a communication system. The communication system may include the terminal device described in the above method embodiments, and network devices (such as access network devices, access and mobility management network elements, and tag management network elements).

[0343] It should be understood that the processor in the embodiments of this application can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0344] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced synchronous DRAM (ESDRAM), synchronous linked DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0345] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0346] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0347] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0348] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0349] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0350] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0351] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0352] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0353] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0354] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0355] 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 that can be easily conceived by those skilled in the art within the scope of the technology 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 by comprising: The method comprises: receiving first information; wherein the first information is used to determine M antenna ports and M spatial layers for transmitting uplink reference signals, the M antenna ports correspond to the M spatial layers one by one; the M spatial layers are part of N spatial layers corresponding to uplink data transmission, and N and M are integers greater than 0; transmitting, according to the first information, first uplink reference signals on the M spatial layers through the M antenna ports.

2. The method of claim 1, wherein, The first information comprises first indication information and second indication information; the first indication information is used to indicate the N spatial layers and N antenna ports corresponding to the N spatial layers one by one, and the second indication information is used to indicate the M spatial layers.

3. The method of claim 1, wherein, The first information comprises first indication information and second indication information, the first indication information is used to indicate the N spatial layers and the M antenna ports, and the second indication information is used to indicate the M spatial layers.

4. The method according to claim 2 or 3, characterized in that, The second indication information is represented by a bit map; wherein the value of each bit in the bit map is used to indicate whether one of the N spatial layers transmits uplink reference signals.

5. The method of claim 1, wherein, The first information is used to indicate the N spatial layers and N antenna ports corresponding to the N spatial layers one by one.

6. The method of claim 1, wherein, The first information is used to indicate the N spatial layers and the M antenna ports.

7. The method according to claim 5 or 6, characterized in that, The method further comprises: determining, according to the first information and preconfigured information, the M antenna ports and the M spatial layers; wherein the preconfigured information is used to indicate the M spatial layers.

8. The method of claim 1, wherein, The first information is used to indicate a first antenna port combination corresponding to the N spatial layers, and the antenna ports in the first antenna port combination are the M antenna ports.

9. The method of claim 8, wherein, The N spatial layers correspond to N antenna ports one by one, the N antenna ports are associated with L antenna port combinations, each antenna port combination in the L antenna port combinations contains a combination of one or more antenna ports in the N antenna ports; the first antenna port combination is one of the L antenna port combinations, and L is an integer greater than 0.

10. The method of claim 9, wherein, The N antenna ports correspond to the same spatial layer as the antenna ports with the same antenna port index in the first antenna port combination.

11. The method according to any one of claims 1-10, characterized in that, The first information is used to indicate an uplink precoding matrix; and transmitting, according to the first information, first uplink reference signals on the M spatial layers through the M antenna ports comprises: transmitting, according to the uplink precoding matrix, the first uplink reference signals on the M spatial layers through the M antenna ports.

12. A communication method characterized by comprising: The method comprises: transmitting first information; wherein the first information is used to determine M antenna ports and M spatial layers for transmitting uplink reference signals, the M antenna ports correspond to the M spatial layers one by one; the M spatial layers are part of N spatial layers corresponding to uplink data transmission, and N and M are integers greater than 0; receiving first uplink reference signals; wherein the first uplink reference signals are transmitted on the M spatial layers through the M antenna ports.

13. The method of claim 12, wherein, The first information comprises first indication information and second indication information; the first indication information is used for indicating the N spatial layers and N antenna ports corresponding to the N spatial layers; and the second indication information is used for indicating the M spatial layers.

14. The method of claim 12, wherein, The first information comprises first indication information and second indication information; the first indication information is used for indicating the N spatial layers and the M antenna ports; and the second indication information is used for indicating the M spatial layers.

15. The method according to claim 13 or 14, characterized in that, The second indication information is represented by a bitmap; and a value of each bit in the bitmap is used for indicating whether an uplink reference signal is transmitted by a spatial layer in the N spatial layers.

16. The method of claim 12, wherein, The first information is used for indicating the N spatial layers and N antenna ports corresponding to the N spatial layers.

17. The method of claim 12, wherein, The first information is used for indicating the N spatial layers and the M antenna ports.

18. The method of claim 12, wherein, The first information is used for indicating a first antenna port combination corresponding to the N spatial layers, and antenna ports in the first antenna port combination are the M antenna ports.

19. The method of claim 18, wherein, The N spatial layers correspond to N antenna ports one by one, the N antenna ports are associated with L antenna port combinations, each antenna port combination in the L antenna port combinations comprises a combination of one or more antenna ports in the N antenna ports; the first antenna port combination is one of the L antenna port combinations, and L is an integer greater than 0.

20. The method of claim 19, wherein, The N antenna ports correspond to the same spatial layer as an antenna port with the same antenna port index in the first antenna port combination.

21. The method of any one of claims 12-20, wherein, The first information is used for indicating an uplink precoding matrix, and the first uplink reference signal is determined according to the uplink precoding matrix.

22. A communications device, characterized by The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer executes the communication method according to any one of claims 1-21.

23. A communications device, characterized by The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer executes the communication method according to any one of claims 1-21. The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer executes the communication method according to any one of claims 1-21. The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer executes the communication method according to any one of claims 1-21.

24. A communication chip, comprising: The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer executes the communication method according to any one of claims 1-21.

25. A computer-readable storage medium, characterized in that, ​ 26. A computer program product, characterised in that, ​

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