Pre-coding method and apparatus

Abstract

Disclosed in the present application are a pre-coding method and apparatus. The method comprises: a distributed unit (DU) performing non-linear pre-coding calculation on the basis of channel information and layer-2 scheduling information, so as to obtain a first pre-coding weight and a second pre-coding weight, wherein the first pre-coding weight is used for a non-linear operation for interference pre-cancellation in the non-linear pre-coding; and sending the layer-2 scheduling information to a radio unit (RU), and further sending the first pre-coding weight and / or the second pre-coding weight. The present method embodiment provides an architecture for enabling non-linear pre-coding, which is used for performing non-linear pre-coding calculation and obtaining a corresponding pre-coding weight, then transmitting the pre-coding weight by means of a fronthaul interface, and finally executing non-linear pre-coding on the basis of the pre-coding weight. Therefore, a non-linear pre-coding process is implemented.

Description

Precoding method and apparatus

[0001] The present application claims priority to the Chinese patent application No. 202510061885.4, filed on January 14, 2025, and entitled "Precoding method and apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of wireless communication, and in particular to a precoding method and apparatus. BACKGROUND

[0003] With the growth of communication service demand, the number of users in a cell increases, which causes serious interference problems. Compared with the traditional single antenna system, the multiple-input multiple-output (MIMO) technology has a larger antenna scale and higher degrees of freedom, and thus can bring higher spectrum efficiency and larger communication capacity. The precoding processing of the transmit signals of the MIMO array can effectively reduce the multi-user interference. The basic idea of transmit signal precoding is that the transmitter maps different data streams to different physical transmit antennas according to certain rules according to the channel state information. This preprocessing optimizes the sending strategy and improves the communication performance. The precoding algorithm is divided into linear precoding and nonlinear precoding according to whether nonlinear operation is introduced. The implementation complexity of linear precoding is relatively low, but in the scenario where the multi-user channel correlation is strong (for example, the user dense deployment scenario), the communication capacity decays significantly. Even in the scenario where the multi-user channel correlation is strong, nonlinear precoding can still effectively reduce the multi-user interference, and has obvious performance gain compared with linear precoding.

[0004] In the open radio access network (O-RAN) protocol, the calculation of linear precoding weights and the transmission of the weights on the fronthaul interface have been implemented through architectures such as weight-based dynamic beamforming (WDBF) and channel-information-based beamforming (CIBF). However, there is no architecture for enabling nonlinear precoding. SUMMARY

[0005] Embodiments of the present application provide a precoding method and apparatus, and provide an architecture for enabling nonlinear precoding, which is used in the nonlinear precoding process.

[0006] In a first aspect, the present application provides a precoding method, comprising: performing nonlinear precoding calculation based on channel information and layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operation of interference pre-cancellation in the nonlinear precoding; and sending the first precoding weight and / or the second precoding weight and the layer 2 scheduling information to a radio unit (RU).

[0007] The above method can be applied to a first communication device, which can be a distributed unit in a network device, or a module (such as a chip system, etc.) in the distributed unit, or a logic node, a logic module or software capable of realizing all or part of the functions of the distributed unit. No limitation is made in this regard.

[0008] The first precoding weight and the second precoding weight are obtained by performing nonlinear precoding calculation by a distributed unit (DU) of a base station. Then, the DU sends at least one of the first precoding weight and the second precoding weight and the layer 2 scheduling information to the RU. If only one of the first precoding weight or the second precoding weight is sent to the RU, the RU calculates the other precoding weight and performs nonlinear precoding in combination with the first precoding weight, the second precoding weight and the layer 2 scheduling information. This process provides an architecture for implementing nonlinear precoding in a base station, and in the case where the DU sends only a single precoding weight, the transmission traffic of the fronthaul interface can be reduced; in the case where the DU sends all precoding weights, the calculation complexity of the RU can be reduced.

[0009] In a feasible implementation, before performing nonlinear precoding calculation based on the channel information and the layer 2 scheduling information, the method further comprises: receiving channel information from the RU; and sending the first precoding weight and / or the second precoding weight to the RU of the access network device, comprising: sending the first precoding weight or the second precoding weight to the RU.

[0010] In this embodiment, the RU performs channel estimation of the SRS and sends the estimated channel information to the DU, the DU performs layer 2 scheduling and precoding calculation based on the channel information to obtain the first precoding weight and the second precoding weight, and then sends the first precoding weight or the second precoding weight to the RU through the fronthaul interface. In this process, the RU calculates the second precoding weight based on the first precoding weight obtained from the DU, or calculates the first precoding weight based on the second precoding weight obtained from the DU, thereby reducing the complexity of the RU in calculating the precoding weight. Moreover, the fronthaul interface only transmits the first precoding weight and does not need to transmit all the weights, thereby reducing the transmission traffic of the fronthaul interface.

[0011] In an implementation, before the non-linear precoding calculation based on the channel information and the layer 2 scheduling information, the method further comprises: receiving a channel sounding reference signal (SRS) from the RU, and obtaining the channel information according to the SRS; and sending the first precoding weight and / or the second precoding weight to a radio unit (RU) in the access network device, including: sending the first precoding weight and the second precoding weight to the RU.

[0012] In the embodiments of the present application, the channel estimation of the SRS is performed by the DU, the layer 2 scheduling is performed based on the channel information, and the first precoding weight and the second precoding weight are obtained through precoding calculation, and then the first precoding weight and the second precoding weight are sent to the RU through the front-haul interface. In this process, the DU performs all the precoding weight calculation, so that the calculation complexity of the RU is simplified to the greatest extent.

[0013] In an implementation, the first precoding weight is a block lower triangular matrix, and the second precoding weight is a unitary matrix, and the block lower triangular matrix and the unitary matrix are generated by performing LQ decomposition on a channel characteristic matrix of a data stream corresponding to each terminal scheduled in the layer 2 scheduling information.

[0014] The first precoding weight and the second precoding weight are obtained through LQ decomposition in the DU based on the channel information and the layer 2 scheduling information, and in the RU, the second precoding weight is obtained through matrix inversion calculation based on the channel information, the layer 2 scheduling information and the first precoding weight, or the first precoding weight is obtained through matrix multiplication calculation based on the channel information, the layer 2 scheduling information and the second precoding weight, when the first precoding weight or the second precoding weight has been obtained. The process of obtaining the second precoding weight or the first precoding weight has a lower calculation complexity than the process of obtaining the precoding weight through LQ decomposition.

[0015] In a second aspect, the present application provides a precoding method. The method comprises: receiving layer 2 scheduling information, and obtaining a first precoding weight and a second precoding weight, wherein the first precoding weight is used for a non-linear operation of interference pre-cancellation in non-linear precoding; and performing non-linear precoding based on the first precoding weight, the second precoding weight and the layer 2 scheduling information.

[0016] The above method can be applied to a second communication device, which can be a radio unit in a network device, or a module (such as a chip system, etc.) in the radio unit, or a logic node, a logic module or software capable of realizing all or part of the functions of the radio unit. This is not limited.

[0017] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the first precoding weight from the DU; and performing matrix inversion calculation based on the channel information, layer 2 scheduling information and the first precoding weight to obtain the second precoding weight.

[0018] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the second precoding weight from the DU; and performing matrix multiplication calculation based on the channel information, layer 2 scheduling information, and the second precoding weight to obtain the first precoding weight.

[0019] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the first precoding weight and the second precoding weight from the DU.

[0020] In one feasible implementation, the first precoding weight is a block lower triangular matrix, and the second precoding weight is a unitary matrix.

[0021] In one feasible implementation, before obtaining the first precoding weight and the second precoding weight, the method further includes: receiving a channel sounding reference signal (SRS) and obtaining channel information based on the SRS; and sending the channel information to the DU, wherein the channel information is used for calculating the first precoding weight and the second precoding weight.

[0022] In one feasible implementation, precoding is performed based on a first precoding weight and a second precoding weight, including: performing interference pre-cancellation on the data stream corresponding to the terminal scheduled on each frequency domain resource unit indicated in the Layer 2 scheduling information based on the first precoding weight to obtain the data stream vector after interference pre-cancellation; and performing filtering processing on the data stream vector based on the second precoding weight to complete the precoding.

[0023] Thirdly, a communication device is provided, which includes units or modules for performing the possible methods in either the first or second aspect described above.

[0024] Fourthly, embodiments of this application provide a communication device, the communication device including at least one processor coupled to a memory; wherein the at least one processor is configured to execute a computer program or instructions stored in the memory, such that the methods that may be implemented in either the first or second aspect described above are executed.

[0025] Fifthly, embodiments of this application provide a communication system, which includes a first communication device and a second communication device, wherein the first communication device is used to perform the method described in any one of the first aspects, and the second communication device is used to perform the method described in any one of the second aspects.

[0026] Sixthly, embodiments of this application provide a computer-readable storage medium storing computer instructions that, when executed, cause the computer to perform the method described in any of the above methods.

[0027] In a seventh aspect, embodiments of this application provide a computer program product, the computer program product comprising: computer program code, which, when executed by a computer, causes the computer to perform the method described in any of the above methods.

[0028] Eighthly, embodiments of this application provide a chip coupled to a memory for reading and executing program instructions in the memory, so that the device in which the chip is located implements the method described in any of the above methods. Attached Figure Description

[0029] The accompanying drawings used in the embodiments of this application are described below.

[0030] Figure 1A is a schematic diagram of the architecture of the communication system used in the embodiments of this application.

[0031] Figure 1B is a schematic diagram of a fronthaul network architecture provided in an embodiment of this application.

[0032] Figure 1C is a schematic diagram of a communication system with a base station function splitting architecture provided in an embodiment of this application.

[0033] Figure 1D is a schematic diagram of a WDBF fronthaul architecture provided in an embodiment of this application.

[0034] Figure 1E is a schematic diagram of a CIBF fronthaul architecture provided in an embodiment of this application.

[0035] Figure 2 is a flowchart of a precoding method provided in an embodiment of this application.

[0036] Figure 3A is a flowchart of another precoding method provided in an embodiment of this application.

[0037] Figure 3B is a schematic diagram of a nonlinear precoding architecture provided in an embodiment of this application.

[0038] Figure 4A is a flowchart of another precoding method provided in an embodiment of this application.

[0039] Figure 4B is a schematic diagram of another nonlinear precoding architecture provided in an embodiment of this application.

[0040] Figure 5A is a flowchart of another precoding method provided in an embodiment of this application.

[0041] Figure 5B is a schematic diagram of another nonlinear precoding architecture provided in an embodiment of this application.

[0042] Figure 6 is a schematic diagram of the structure of a communication device provided in an embodiment of this application.

[0043] Figure 7 is a simplified structural diagram of a network device provided in an embodiment of this application.

[0044] Figure 8 is a schematic diagram of a RAN chip structure provided in an embodiment of this application.

[0045] Figure 9 is a simplified structural diagram of a UE provided in an embodiment of this application. Detailed Implementation

[0046] The technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. The terms "system" and "network" in the embodiments of this application can be used interchangeably. Unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship; for example, A / B can represent A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be one or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish between network elements and similar items with essentially the same function. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0047] References to "one embodiment" or "some embodiments" in the embodiments described in this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0048] 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.

[0049] In the embodiments of this application, the terms "information," "signal," "message," "channel," and "singaling" 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.

[0050] The following detailed embodiments further illustrate the objectives, technical solutions, and beneficial effects of this application. It should be understood that the following are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made based on the technical solutions of this application should be included within the scope of protection of this application.

[0051] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0052] The system architecture involved in the embodiments of this application is described below.

[0053] Figure 1A is a schematic diagram of the architecture of the communication system 1000 used in an embodiment of this application. As shown in Figure 1A, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The wireless access network 100 may include at least one network device (110a and 110b in Figure 1A) and at least one terminal device (120a-120j in Figure 1A). The terminal device is wirelessly connected to the network device, and the network device is wirelessly or wired connected to the core network. The core network device and the network device may be independent physical devices, or the functions of the core network device and the logical functions of the network device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the network device. Terminal devices and network devices can be interconnected via wired or wireless means. Figure 1A is only a schematic diagram; the communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1A.

[0054] Optionally, in practical applications, the wireless communication system may simultaneously include one or more network devices (also known as access network devices) and one or more terminal devices. A network device may simultaneously serve one or more terminal devices. A terminal device may also simultaneously access one or more network devices. This application embodiment does not limit the number of terminal devices and network devices included in the wireless communication system.

[0055] In this context, a network device can be an entity on the network side used to transmit or receive signals. A network device can also be an access device that allows terminal devices to wirelessly connect to the wireless communication system; for example, a network device can be a base station. Base stations can broadly encompass various names listed below, or be interchangeable with them, such as: radio access network (RAN) node, Node B, evolved Node B (eNB), next-generation Node B (gNB), access network equipment in open radio access network (O-RAN), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNB (MeNB), secondary eNB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, building baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), and distributed unit (CU). Network equipment includes units (DU), radio units (RU), centralized unit control plane (CU-CP) nodes, centralized unit user plane (CU-UP) nodes, positioning nodes, etc. Base stations can be macro base stations, micro base stations, relay nodes, donor nodes, or similar entities, or combinations thereof. Network equipment can also refer to communication modules, modems, or chips installed within the aforementioned equipment or devices. Network equipment can also be mobile switching centers and equipment that performs base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications; network-side equipment in 6G networks; and equipment performing base station functions in future communication systems. Network equipment can support networks using the same or different access technologies.The embodiments of this application do not limit the specific technology or device form used in the network device.

[0056] Network devices can be fixed or mobile. For example, base stations 110a and 110b are stationary and are responsible for wireless transmission and reception in one or more cells from terminal device 120. The helicopter or drone 120i shown in Figure 1A can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station 120i. In other examples, the helicopter or drone (120i) can be configured as a terminal device communicating with base station 110b.

[0057] In this application, the communication device used to implement the above-mentioned network access functions can be an access network device, a network device with some access network functions, or a device capable of supporting the implementation of access network functions, such as a chip system, hardware circuit, software module, or hardware circuit plus software module. This device can be installed in the access network device or used in conjunction with the access network device. In the method of this application, the example of an access network device being used as the communication device to implement the access network device functions is described.

[0058] A terminal device can be a user-side entity used to receive or transmit signals, such as a mobile phone. Terminal devices can be used to connect people, things, and machines. They can communicate with one or more core networks via network devices. Terminal devices include handheld devices with wireless connectivity, other processing devices connected to a wireless modem, or in-vehicle devices. Terminal devices can be portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile devices. Terminal devices can be widely used in various scenarios, such as cellular communication, D2D, V2X, point-to-point (P2P), machine-to-machine (M2M), machine-type communication (MTC), Internet of Things (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, autonomous delivery, and mobility.Examples of terminal devices include: user equipment (UE) conforming to the 3rd Generation Partnership Project (3GPP) standard, fixed equipment, mobile equipment, handheld devices, wearable devices, cellular phones, smartphones, session initiated protocol (SIP) phones, laptops, personal computers, smart books, vehicles, satellites, global positioning system (GPS) devices, drones, helicopters, aircraft, ships, remote control devices, smart home devices, industrial equipment, personal communication service (PCS) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), wireless network cameras, tablets, handheld computers, mobile internet devices (MIDs), wearable devices such as smartwatches, VR devices, AR devices, wireless terminals in industrial control, terminals in vehicle-to-everything (V2X) systems, wireless terminals in self-driving vehicles, wireless terminals in smart grids, wireless terminals in transportation safety, and smart city applications. Wireless terminals in various scenarios include smart gas pumps, high-speed rail terminals, and smart home terminals such as smart speakers, smart coffee machines, and smart printers. Terminal devices can be wireless devices in these scenarios or devices installed on wireless devices, such as communication modules, modems, or chips. Terminal devices can also be called terminals, user equipment (UE), mobile stations (MS), mobile terminals (MT), etc. Terminal devices can also be used in future wireless communication systems. Terminal devices can be used in dedicated network equipment or general-purpose equipment. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

[0059] Optionally, the terminal device can be used to act as a base station. For example, the UE can act as a scheduling entity, providing sidelink signaling between UEs in V2X, D2D, or P2P, etc. As shown in Figure 1A, cellular phone 120a and car 120b communicate with each other using sidelink signaling. Cellular phone 120a communicates with smart home device 120e without relaying communication signals through base station 110b.

[0060] In this application, the communication device used to implement the functions of the terminal device can be a terminal device, a terminal device having some of the functions of the aforementioned terminal device, or a device capable of supporting the implementation of the functions of the aforementioned terminal device, such as a chip system. This device can be installed in the terminal device or used in conjunction with the terminal device. In this application, the chip system can be composed of chips or include chips and other discrete components. The technical solutions provided in this application are described using the example of a terminal device or UE as the communication device.

[0061] Optionally, wireless communication systems typically consist of cells, with base stations providing cell management and sending signals to one or more mobile stations within the cell.

[0062] A mobile station (MS) provides communication services. A base station includes a baseband unit (BBU) and a remote radio unit (RRU). The BBU and RRU can be located in different locations; for example, the RRU can be deployed remotely to a high-traffic area, while the BBU is located in a central equipment room. Alternatively, the BBU and RRU can be located in the same equipment room. The BBU and RRU can also be different components within the same rack. Optionally, a cell can correspond to one carrier or a member carrier.

[0063] In some deployments, the network devices mentioned in the embodiments of this application may be devices including CU, DU, or CU and DU, or devices with control plane CU nodes (central unit-control plane (CU-CP)) and user plane CU nodes (central unit-user plane (CU-UP)) and DU nodes. For example, the network devices may include gNB-CU-CP, gNB-CU-UP, and gNB-DU.

[0064] In some deployments, one or more RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes each implementing some of the base station's functions. For example, RAN nodes can be CUs, DUs, CU-CPs, CU-UPs, or RUs. CUs and DUs can be configured separately or included in the same network element, such as a BBU. RUs can be included in radio frequency equipment or radio frequency units, such as RRUs, AAUs, or RRHs.

[0065] Wireless communication networks are divided into three parts: access network, bearer network, and core network. The access network mainly consists of base stations. Figure 1B shows a schematic diagram of the fronthaul network architecture of a 4th generation (4G) / 5G mobile communication network. In a 4G network, a base station typically includes a BBU, RRU, and feeder, and is connected to the core network via the bearer network. The 3rd Generation Partnership Project (3GPP) rd The Generation Partnership Project (3GPP) New Radio (NR) protocol specifies that the functional entities of a 5G base station (next-generation nodeB, gNodeB) include the CU and DU; the Open Radio Access Network (ORAN) Alliance defines the base station functional entities consisting of the CU, DU, and RU. As shown in Figure 1B, the interface between the BBU (DU) and RRU (RU) is defined as "fronthaul", the signal transmission between the BBU and the core network is defined as "backhaul", and the transmission between the DU and CU is defined as "midhaul".

[0066] Figure 1C illustrates a communication system with a base station function-segmented architecture. Data between the UE and the server is transmitted through the base station and the core network. The base station function can be divided into three functional modules: CU, DU, and RU. The 5G core network can connect one or more CUs. A CU can connect to one or more DUs via a midhaul link, and a DU can connect to one or more RUs via a fronthaul link. An RU can establish a physical transmission link with one or more UEs. CU, DU, and RU can be deployed in different physical devices. The system architecture can also include scenarios where the base station function is split into two functional modules. For example, if the CU and DU functions are deployed in the same physical device, then the CU and DU functions can be considered as one functional entity; or if the DU and RU functions are deployed in the same physical device, then the DU and RU functions can be considered as one functional entity. This communication system is not limited to 5G network architecture; it is also applicable to Long Term Evolution (LTE) networks and future network architectures, as long as the network architecture has communication connectivity capabilities.

[0067] RAN nodes can support one or more types of fronthaul interfaces, each corresponding to a DU and RU with different functions. If the fronthaul interface between the DU and RU is a common public radio interface (CPRI), the DU is configured to implement one or more baseband functions, and the RU is configured to implement one or more radio frequency functions. If the fronthaul interface between the DU and RU is another type of interface, relative to CPRI, some downlink and / or uplink baseband functions, such as, for downlink, precoding, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix addition (CP), are moved from the DU to the RU; and for uplink, one or more of digital beamforming (BF), or fast Fourier transform (IFFT) / cyclic prefix removal (CP), are moved from the DU to the RU. In one possible implementation, the interface can be an enhanced common public radio interface (eCPRI). Under the eCPRI architecture, the segmentation between DU and RU differs, corresponding to different categories (Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, F.

[0068] Taking eCPRI Cat A as an example, for downlink transmission, the DU is configured to implement one or more functions before and after layer mapping (i.e., coding, rate matching, scrambling, modulation, and layer mapping), while other functions after layer mapping (e.g., RE mapping, digital beamforming (BF), or one or more functions of inverse fast Fourier transform (IFFT) / adding cyclic prefix (CP)) are moved to the RU. For uplink transmission, the DU is configured to implement one or more functions before and after de-RE mapping (i.e., decoding, de-rate matching, descrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping), while other functions after de-RE mapping (e.g., digital BF or one or more functions of fast Fourier transform (FFT) / removing CP) are moved to the RU. It is understandable that the functional descriptions of the DU and RU corresponding to various types of eCPRI can be found in the eCPRI protocol, and will not be elaborated here.

[0069] In one possible design, the processing unit in the BBU used to implement baseband functions is called the baseband high (BBH) unit, and the processing unit in the RRU / AAU / RRH used to implement baseband functions is called the baseband low (BBL) unit.

[0070] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0071] In this embodiment, the apparatus for implementing the functions of a network device can be a network device itself; it can also be an apparatus capable of supporting the network device in implementing those functions, such as a chip system, hardware circuit, software module, or a hardware circuit plus a software module. This apparatus can be installed in the network device or used in conjunction with the network device. In this embodiment, the example of a network device being used to implement the functions of a network device is provided only and does not constitute a limitation on the solutions described in this embodiment.

[0072] It is understood that this application can be used in communication between network devices and terminal devices.

[0073] Communication between network devices and terminal devices follows a specific protocol layer structure. This protocol layer structure can include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure can include the functions of protocol layers such as the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical layer. Similarly, the user plane protocol layer structure can include the functions of protocol layers such as the PDCP layer, the RLC layer, the MAC layer, and the physical layer. In one possible implementation, a service data adaptation protocol (SDAP) layer can be included above the PDCP layer.

[0074] Optionally, the protocol layer structure between network devices and terminal devices may also include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0075] Taking data transmission between network devices and terminal devices as an example, data transmission needs to pass through user plane protocol layers, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. The SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer can also be collectively referred to as the access layer. Based on the direction of data transmission, it is divided into sending and receiving; each of these layers is further divided into a sending part and a receiving part. Taking downlink data transmission as an example, after the PDCP layer obtains data from the upper layer, it transmits the data to the RLC layer and MAC layer. The MAC layer then generates a transport block, and finally, it is wirelessly transmitted through the physical layer. Data is encapsulated in corresponding ways at each layer. For example, data received by a layer from the upper layer is considered a Service Data Unit (SDU) of that layer. After encapsulation by that layer, it becomes a Protocol Data Unit (PDU) and is then passed to the next layer.

[0076] For example, the terminal device may also have an application layer and a non-access layer. The application layer can be used to provide services to applications installed on the terminal device. For instance, downlink data received by the terminal device can be sequentially transmitted from the physical layer to the application layer, and then provided to the application by the application layer. Alternatively, the application layer can acquire data generated by the application and sequentially transmit the data to the physical layer for transmission to other communication devices. The non-access layer can be used to forward user data, such as forwarding uplink data received from the application layer to the SDAP layer, or forwarding downlink data received from the SDAP layer to the application layer.

[0077] It should be understood that the number and type of each device in the communication system shown in Figure 1A are for illustrative purposes only, and this application is not limited thereto. In actual applications, the communication system may include more terminal devices, more access network devices, and other network elements, such as core network devices and / or network elements used to implement artificial intelligence functions.

[0078] It is understandable that all or part of the functions implemented by one or more of the terminal devices, access network devices, core network devices, or network elements used to implement artificial intelligence functions can be virtualized, that is, implemented through one or more of dedicated or general-purpose processors and corresponding software modules. Among these, the terminal devices and access network devices involve air interface transmission, and the transmit and receive functions of this interface can be implemented in hardware. Core network devices, such as operation administration and maintenance (OAM) network elements, can also be virtualized. Optionally, one or more of the functions of the virtualized terminal devices, access network devices, core network devices, or network elements used to implement artificial intelligence functions can be implemented by cloud devices, such as cloud devices in over-the-top (OTT) systems.

[0079] The prior art of the embodiments of this application is described below.

[0080] 1. Transmitted signal precoding technology

[0081] With the increasing demand for communication services, the number of users within a cell is growing, leading to significant interference problems. Compared to traditional single-antenna systems, MIMO technology offers larger antenna sizes and greater degrees of freedom, resulting in higher spectral efficiency and greater communication capacity. Precoding the transmitted signals of a MIMO array can effectively reduce multi-user interference. The basic idea of ​​transmit signal precoding is that the transmitter maps different data streams to different physical transmit antennas according to certain rules based on channel state information. This preprocessing method optimizes the transmission strategy and improves communication performance. Precoding algorithms are classified into linear precoding and nonlinear precoding based on whether they involve nonlinear operations. Common linear precoding algorithms in MIMO systems include zero-force precoding, matched filter (MF) precoding, and minimum mean square error (MMSE) precoding. While linear precoding has lower implementation complexity, its communication capacity attenuation is significant in scenarios with strong multi-user channel correlation (e.g., densely populated user deployments). Even in scenarios with strong multi-user channel correlation, nonlinear precoding can still effectively reduce multi-user interference, and has a significant performance gain compared to linear precoding.

[0082] 2. Nonlinear precoding

[0083] Consider the following multi-user MIMO system: the number of base station transmit antennas is N. T The number of data streams transmitted by the base station to the k-th UE is N. kThe total number of UEs (or the total number of users. In this embodiment, a user is a user terminal, so users and UEs can be used interchangeably) is K, and the total number of data streams transmitted by the base station is K. The downlink channel matrix can be represented as:

[0084] in, Let be the downlink channel matrix corresponding to the k-th UE, (·) H This represents the conjugate transpose of a matrix.

[0085] The steps of nonlinear precoding can be broken down as follows:

[0086] Step 1: The base station performs LQ decomposition on the downlink channel matrix H, decomposing the downlink channel matrix into the product of a block lower triangular matrix and a unitary matrix, i.e.:

[0087] H = LQ H

[0088] Where L is a block lower triangular matrix, Q is a unitary matrix, and we have Q×Q H =I. The equivalent channel matrix L can be expressed by the formula:

[0089] Each diagonal block L k The dimension is N k ×N k .

[0090] Step 2: Since the equivalent channel matrix is ​​a block lower triangular matrix, the k-th UE is only affected by interference from the previous k-1 UEs. Therefore, the base station can perform interference pre-cancellation on the transmitted data stream. This step can be expressed by the formula:

[0091] in Let be the original data stream vector transmitted by the base station to the k-th UE. Let be the data stream vector after interference pre-cancellation transmitted by the base station to the i-th (i<=k-1) UE. Let be the data stream vector transmitted by the base station to the k-th UE after interference pre-cancellation, mod(·) is the modulus operation, τ is determined by the modulation order, and (·) -1 The expression represents the matrix inversion operation, l k It is an integer.

[0092] Step 3: The base station uses a forward filter Q to make the final transmitted signal x = Qs′. in This is the transmitted data stream vector after interference pre-cancellation in step 2. After the transmitted signal passes through the channel, the received signal y can be expressed by the formula:

[0093] Where n is the channel noise, as can be seen from the above formula, multi-user interference is effectively eliminated.

[0094] 3. Linear precoding fronthaul architecture

[0095] 3.1 WDBF Fronthaul Architecture

[0096] The O-RAN protocol defines a WDBF fronthaul architecture for implementing linear precoding. In this method, the DU needs to know the antenna characteristics of the RU, including the number of antenna elements in the vertical and horizontal directions and the antenna element spacing. Based on the channel information and the RU's antenna array, the DU generates precoding weights, each corresponding to a beam identifier (beamId) value. The DU sends the precoding weights and their corresponding beamIds to the RU. Referring to Figure 1D, which is a schematic diagram of a WDBF fronthaul architecture provided in an embodiment of this application, the data processing and transmission flow between the DU, RU, and UE under this fronthaul architecture is as follows:

[0097] (1) The DU acquires the channel sounding reference signal (SRS) sent by the UE, and performs uplink channel estimation based on the SRS to obtain the uplink channel estimation result. With the help of the reciprocity of uplink and downlink channels in the time division duplex (TDD) system, the DU can obtain the downlink channel estimation result.

[0098] (2) The DU performs layer 2 (L2) scheduling based on the channel estimation results of the SRS. Layer 2 scheduling involves a multiple users (MU) pairing process, which determines the specific number of users and their corresponding data streams to be scheduled on each frequency domain resource unit.

[0099] (3) DU calculates the MU precoding weights based on the channel estimation results of SRS and the layer 2 scheduling results, and sends the MU precoding weights and layer 2 scheduling information to RU through the fronthaul interface.

[0100] (4) RU performs linear precoding based on MU precoding weights and layer 2 scheduling information.

[0101] 3.2 CIBF Fronthaul Architecture

[0102] The O-RAN protocol also defines a CIBF fronthaul architecture for implementing linear precoding. In this method, the DU provides scheduling information to the RU on a slot-by-slot basis and periodically (usually less than per slot) provides channel information for each UE to the RU. The RU calculates the beamforming weights for each slot based on the channel information and scheduling information. Referring to Figure 1E, which is a schematic diagram of a CIBF fronthaul architecture provided in an embodiment of this application, the data processing and transmission flow between the DU, RU, and UE under this fronthaul architecture is as follows:

[0103] (1) The DU obtains the SRS sent by the UE, and performs uplink channel estimation based on the SRS to obtain the uplink channel estimation result. Taking advantage of the reciprocity of uplink and downlink channels in the TDD system, the DU can obtain the downlink channel estimation result. The DU sends the channel estimation result of the SRS to the RU through the fronthaul interface.

[0104] (2) The DU performs Layer 2 scheduling based on the SRS channel estimation results. Layer 2 scheduling involves MU pairing. The DU sends the Layer 2 scheduling results to the RU.

[0105] (3) The RU calculates the MU precoding weights based on the SRS channel estimation and layer 2 scheduling results.

[0106] (4) RU performs linear precoding based on MU precoding weights and layer 2 scheduling information.

[0107] For the WDBF architecture, precoding weights need to be transmitted from the DU to the RU. However, the data format for transmitting precoding weights defined in the current O-RAN protocol only supports the transmission of linear precoding weights and does not support the transmission of nonlinear precoding weights. For the CIBF architecture, the complete calculation of precoding weights needs to be performed on the RU, which introduces additional computational complexity requirements for the RU and makes implementation more difficult.

[0108] Example 1: Based on the above description, please refer to Figure 2, which is a flowchart of a precoding method provided in this application embodiment. As shown in Figure 2, the method includes the following steps:

[0109] 201. The distributed unit (DU) performs nonlinear precoding calculations based on channel information and layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operations in nonlinear precoding.

[0110] The channel information obtained in this application embodiment mainly refers to downlink channel information. Its acquisition method is as described in the aforementioned WDBF or CIBF fronthaul architecture: uplink channel estimation can be performed first based on SRS to obtain the uplink channel estimation result, or uplink channel information. Then, the downlink channel estimation result, or downlink channel information, is determined based on the dissimilarity of the uplink and downlink channels (this process can also be called performing SRS channel estimation).

[0111] In this embodiment of the application, the DU obtains downlink channel information in the following two ways (not shown in the figure):

[0112] (1) The RU obtains the SRS sent by the UE, performs channel estimation based on the SRS to obtain downlink channel information and sends it to the DU.

[0113] (2) The RU obtains the SRS sent by the UE and sends the SRS to the DU. The DU performs channel estimation based on the SRS to obtain downlink channel information.

[0114] After obtaining downlink channel information, the DU performs Layer 2 scheduling, or in other words, acquires Layer 2 scheduling information. This process includes acquiring a specific number of users scheduled on each frequency domain resource unit and their corresponding data streams. The Layer 2 scheduling information may include the contents shown in Table 1 below:

[0115] Table 1

[0116] In Table 1 above, "user" manifests as a terminal during communication, and therefore can be replaced with "terminal," "user terminal," etc., without limitation. Frequency domain resource units can be any of the following: RE, RE bundle, resource block (RB), physical resource block (PRB), or PRB bundle.

[0117] In this embodiment, the calculation of nonlinear precoding based on channel information and Layer 2 scheduling information yields a first precoding weight and a second precoding weight. The first precoding weight is used for nonlinear operations in nonlinear precoding, specifically for interference pre-cancellation; the second precoding weight is used for linear operations in nonlinear precoding, specifically for filtering. Specifically, the first precoding weight can be a block lower triangular matrix used for nonlinear operations in interference pre-cancellation, as described in step 2 of the aforementioned nonlinear precoding. The second precoding weight can be a unitary matrix used for linear operations in the filtering process, as described in step 3 of the aforementioned nonlinear precoding.

[0118] For example, the calculation of nonlinear precoding based on channel information and layer 2 scheduling information includes: first determining the downlink channel matrix corresponding to the channel information according to the layer 2 scheduling information, and then performing LQ decomposition on the downlink channel matrix.

[0119] Specifically, the downlink channel matrix is ​​determined based on Layer 2 scheduling information, including: performing a MU pairing process; determining the data streams of users scheduled on each frequency domain resource unit based on channel information and Layer 2 scheduling information; that is, different data streams of different UEs are divided into different combinations, each combination uses one frequency domain resource unit, and different data streams within each frequency domain resource unit are spatially multiplexed. Frequency division multiplexing is performed between different groups. Furthermore, the correlation of channel information between different UEs on the same frequency domain resource unit is lower than a preset threshold. Each frequency domain resource unit corresponds to a sub-downlink channel matrix H, which may include H0... k , represents the downlink channel matrix corresponding to the k-th user in this frequency domain resource unit.

[0120] For example, the channel estimation results for each frequency domain resource element (including frequency domain resource 1 to frequency domain resource 4) of the full frequency band of UE1 to UE2 can be found in Table 2:

[0121] Table 2

[0122] As shown in Table 1, UE1 and UE2 correspond to two data streams in each frequency domain resource unit. Layer 2 scheduling involves a MU pairing process. The results of MU pairing are shown in Table 3 below:

[0123] Table 3

[0124] As can be seen, different UE data streams within a group are distinguished by channel correlation, while those between groups are distinguished by frequency.

[0125] The downlink channel matrix is ​​decomposed using LQ decomposition, which involves performing LQ decomposition on each H according to a certain rule to obtain a first precoding weight L and a second precoding weight Q. L can be a lower triangular block matrix, and Q can be a unitary matrix.

[0126] 202. The DU sends Layer 2 scheduling information to the radio frequency unit RU, and also sends a first precoding weight and / or a second precoding weight. Correspondingly, the RU receives the Layer 2 scheduling information, and also receives the first precoding weight and / or the second precoding weight.

[0127] After obtaining the first and second precoding weights, DU can perform operations in the following ways:

[0128] (1) Send the first precoding weight and layer 2 scheduling information to the RU.

[0129] The first precoding weight is used for nonlinear operations in nonlinear precoding and can be called the nonlinear precoding weight. At this point, the fronthaul interface needs to support the data format for transmitting the nonlinear precoding weight.

[0130] For example, the first precoding weight is a lower triangular matrix L of the block, and its corresponding dimension is The fronthaul interface needs to support Transmission of data in dimensional formats. Where N... f This represents the total number of UE data streams scheduled on frequency domain resource unit f.

[0131] (2) Send the second precoding weight and layer 2 scheduling information to the RU.

[0132] The second precoding weight is used for linear operations in nonlinear precoding and can be called the linear precoding weight. Therefore, the second precoding weight can reuse the data format of the linear precoding weight.

[0133] For example, the second precoding weight is a unitary matrix Q, whose dimension is the number of base station transmit antennas multiplied by the number of UE data streams scheduled on that frequency domain resource element. This dimension is similar to that of the linear precoding weight, so the fronthaul interface can reuse the data format of the linear precoding weight to transmit the second precoding weight.

[0134] (3) Send the first precoding weight, the second precoding weight, and the layer 2 scheduling information to the RU.

[0135] In this scenario, the DU needs to send both the first and second precoding weights. Therefore, the fronthaul interface must simultaneously support data formats with linear precoding weights and also add data formats supporting non-linear precoding weights. The newly added data format supporting non-linear precoding weights is used to support dimensions of... The transmission of the first precoding weight. The data format of the linear precoding weight is used to support the transmission of the first precoding weight with a dimension of the number of base station transmit antennas × the number of UE data streams scheduled on this frequency domain resource element.

[0136] Specifically, when transmitting the first precoding weight and the second precoding weight, the first precoding weight, the identifier of the first precoding weight, the second precoding weight, and the identifier of the second precoding weight are transmitted through the fronthaul interface, so that the RU can distinguish the first precoding weight and the second precoding weight after receiving the information.

[0137] 203. RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0138] The DU sends the first precoding weight and / or the second precoding weight, as well as the Layer 2 scheduling information, including the three methods mentioned above. Correspondingly, the RU receives the following content:

[0139] (1) First precoding weight and layer 2 scheduling information.

[0140] If the RU only receives the first precoding weight and layer 2 scheduling information sent by the DU, then the RU needs to further calculate the second precoding weight and then perform nonlinear precoding based on the first precoding weight, the second precoding weight and the layer 2 scheduling information.

[0141] (2) Second precoding weights and Layer 2 scheduling information.

[0142] If the RU only receives the second precoding weight and layer 2 scheduling information sent by the DU, then the RU needs to further calculate the first precoding weight and then perform nonlinear precoding based on the first precoding weight, the second precoding weight and the layer 2 scheduling information.

[0143] (3) First precoding weight, second precoding weight and layer 2 scheduling information.

[0144] If the RU receives the first precoding weight, the second precoding weight, and the layer 2 scheduling information sent by the DU, then the RU can directly perform nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0145] For example, the RU performs nonlinear precoding based on a first precoding weight, a second precoding weight, and layer 2 scheduling information, including:

[0146] First, based on the first precoding weight, interference pre-cancellation is performed on the data streams corresponding to the terminals scheduled on each frequency domain resource unit indicated in the Layer 2 scheduling information to obtain the data stream vector after interference pre-cancellation. The specific calculation process can be found in step 2 of the aforementioned nonlinear precoding process.

[0147] Then: the data stream vector is filtered based on the second precoding weights to complete the precoding. For the specific calculation process, please refer to step 3 in the aforementioned nonlinear precoding process.

[0148] As can be seen, in this embodiment, the distributed unit (DU) of the base station performs nonlinear precoding calculations to obtain a first precoding weight and a second precoding weight. Then, the DU sends at least one of the first and second precoding weights, along with Layer 2 scheduling information, to the RU. If only one of the first or second precoding weights is sent to the RU, the RU calculates the other precoding weight and performs nonlinear precoding by combining the first and second precoding weights with the Layer 2 scheduling information. This process provides an architecture for implementing nonlinear precoding in the base station. Furthermore, when the DU sends only a single precoding weight, it reduces the transmission traffic of the fronthaul interface; when the DU sends all precoding weights, it reduces the computational complexity of the RU.

[0149] Example 2: This application example provides a detailed description of the method by which the DU sends the first precoding weight to the RU through the fronthaul interface.

[0150] Referring to Figure 3A, which is a flowchart of another precoding method provided in an embodiment of this application, the method includes the following steps:

[0151] 301. The radio frequency unit RU obtains channel information by performing channel estimation based on the SRS.

[0152] 302. The RU sends the channel information to the distributed unit DU. Correspondingly, the DU receives the channel information.

[0153] In this embodiment of the application, the RU performs channel estimation based on the SRS obtained from the UE to obtain (downlink) channel information, and sends it to the DU.

[0154] 303. The distributed unit (DU) performs nonlinear precoding calculations based on channel information and layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operations in nonlinear precoding.

[0155] This step is the same as step 201 in the aforementioned embodiment, and will not be repeated here.

[0156] 304. The DU sends the first precoding weight and layer 2 scheduling information to the radio frequency unit RU. Correspondingly, the RU receives the first precoding weight and layer 2 scheduling information.

[0157] In this embodiment, the DU only sends the first precoding weight to the RU. Since the first precoding weight is a non-linear precoding weight (e.g., a lower triangular block matrix), the fronthaul interface between the DU and the RU needs to support the data format for transmitting the non-linear precoding weight.

[0158] For example, the first precoding matrix is ​​a block lower triangular matrix L. In each frequency domain resource element, the dimension of L is the number of UE data streams scheduled in that frequency domain resource element multiplied by the number of scheduled UE data streams. Therefore, the dimension of the first precoding weight in each frequency domain resource element is... Each weight corresponds to a user identifier and a user data stream identifier, where N f This represents the total number of UE data streams scheduled on frequency domain resource unit f. The fronthaul interface between DU and RU needs to support a transmission dimension of... The data format.

[0159] Optionally, the DU may also send an identifier corresponding to the first precoding weight to the RU, so that the RU can determine that the received weight belongs to the first precoding weight in the nonlinear precoding based on the identifier corresponding to the first precoding weight.

[0160] 305. RU calculates the second precoding weight based on channel information and the first precoding weight.

[0161] After receiving the first precoding weight, the RU can calculate the second precoding weight based on the channel information and the first precoding weight since the RU has already obtained the channel information through SRS channel estimation.

[0162] Optionally, the second precoding weight is obtained by matrix inversion based on the channel information, layer 2 scheduling information and the first precoding weight.

[0163] For example, the channel information is calculated by the RU. After receiving the Layer 2 scheduling information sent by the DU, the RU determines the downlink channel matrix corresponding to the channel information based on the Layer 2 scheduling information, so that the RU obtains the same downlink channel matrix as the DU when performing nonlinear precoding calculations. Then, the second precoding weight is obtained by matrix inversion calculation based on the downlink channel matrix and the first precoding weight.

[0164] As described in the previous section on nonlinear precoding techniques, if L = HQ, then Q = LH H .

[0165] Where L represents the first precoding weight, Q represents the second precoding weight, and H represents the downlink channel matrix. H This represents the conjugate transpose of the downlink channel matrix.

[0166] 306. RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0167] The RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information. Refer to the description of step 203 in the aforementioned embodiment one, which will not be repeated here.

[0168] The communication process in steps 301 to 306 above can also be represented by an architecture diagram. Referring to Figure 3B, which is a schematic diagram of a nonlinear precoding architecture provided in an embodiment of this application, the architecture includes a DU and a RU, which communicate via a fronthaul interface. The RU receives the SRS sent by the UE and performs channel estimation, sending the channel information (channel estimation result) to the DU (while also storing the channel information itself). The DU performs Layer 2 scheduling based on the channel information to obtain Layer 2 scheduling information. Then, based on the Layer 2 scheduling information and the channel information, it performs precoding calculation (LQ decomposition) to obtain a first precoding weight and a second precoding weight. The fronthaul interface between the DU and RU transmits the first precoding weight and the Layer 2 scheduling information. The RU obtains the downlink channel matrix based on the channel information and the Layer 2 scheduling information, and calculates the second precoding weight based on the downlink channel matrix and the first precoding weight. Finally, the RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the Layer 2 scheduling information.

[0169] As can be seen, in this embodiment, the RU performs channel estimation for SRS and sends the estimated channel information to the DU. The DU then performs Layer 2 scheduling based on the channel information and calculates the first and second precoding weights. The first precoding weight is then sent back to the RU via the fronthaul interface. In this process, the RU calculates the second precoding weight based on the first precoding weight obtained from the DU, reducing the complexity of the RU's precoding weight calculation. Furthermore, the fronthaul interface only transmits the first precoding weight instead of all weights, reducing the transmission traffic of the fronthaul interface.

[0170] Example 3: This application example provides a detailed description of the method by which the DU sends the second precoding weight to the RU through the fronthaul interface.

[0171] Referring to Figure 4A, which is a flowchart of another precoding method provided in an embodiment of this application, the method includes the following steps:

[0172] 401. The radio frequency unit RU obtains channel information by performing channel estimation based on the SRS.

[0173] 402. The RU sends the channel information to the distributed unit DU. Correspondingly, the DU receives the channel information.

[0174] In this embodiment of the application, the RU performs channel estimation based on the SRS obtained from the UE to obtain channel information, and then sends it to the DU.

[0175] 403. The distributed unit (DU) performs nonlinear precoding calculations based on channel information and layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operations in nonlinear precoding.

[0176] This step is the same as step 201 in the aforementioned embodiment, and will not be repeated here.

[0177] 404. The DU sends the second precoding weight and layer 2 scheduling information to the radio frequency unit RU. Correspondingly, the RU receives the second precoding weight and layer 2 scheduling information.

[0178] The second precoding weight can be a linear coding weight (e.g., a unitary matrix). In this case, the fronthaul interface between DU and RU can reuse the data format supported by the transmission precoding weight during linear precoding.

[0179] Furthermore, in each frequency domain resource unit, the dimension of the second precoding weight is the number of base station transmit antennas multiplied by the number of UE data streams scheduled in that frequency domain resource unit. Each weight corresponds to a user identifier and a user data stream identifier. The transmission time of the second precoding weight and Layer 2 scheduling information is generally short, and its time granularity can be equal to or less than the time length of a time slot.

[0180] Optionally, the DU may also send an identifier corresponding to the second precoding weight to the RU, so that the RU can determine that the received weight belongs to the second precoding weight in the nonlinear precoding based on the identifier corresponding to the second precoding weight.

[0181] 405. RU calculates the first precoding weight based on channel information and the second precoding weight.

[0182] After receiving the second precoding weight, the RU can calculate the first precoding weight based on the channel information and the second precoding weight since the RU has already obtained the channel information through SRS channel estimation.

[0183] Optionally, the first precoding weight is obtained by matrix multiplication based on the channel information, layer 2 scheduling information, and the second precoding weight.

[0184] For example, the channel information is calculated by the RU. After receiving the Layer 2 scheduling information sent by the DU, the RU determines the downlink channel matrix corresponding to the channel information based on the Layer 2 scheduling information, so that the RU obtains the same downlink channel matrix as the DU when performing nonlinear precoding calculations. Then, the first precoding weight is obtained by matrix multiplication based on the downlink channel matrix and the second precoding weight.

[0185] As described in the previous section on nonlinear precoding techniques, L = HQ. Since RU has already obtained H and Q, L can be calculated.

[0186] Where L represents the first precoding weight, Q represents the second precoding weight, and H represents the downlink channel matrix.

[0187] 406. RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0188] The RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information. Refer to the description of step 203 in the aforementioned embodiment one, which will not be repeated here.

[0189] The communication process in steps 401 to 406 above can also be represented by an architecture diagram. Referring to Figure 4B, which is a schematic diagram of another nonlinear precoding architecture provided in this embodiment, the architecture includes a DU and a RU, which communicate via a fronthaul interface. The RU receives the SRS sent by the UE and performs channel estimation, sending the channel information (channel estimation result) to the DU (while also storing the channel information itself). The DU performs Layer 2 scheduling based on the channel information to obtain Layer 2 scheduling information. Then, based on the Layer 2 scheduling information and the channel information, it performs precoding calculation (LQ decomposition) to obtain a first precoding weight and a second precoding weight. The fronthaul interface between the DU and RU transmits the second precoding weight and the Layer 2 scheduling information. The RU obtains the downlink channel matrix based on the channel information and the Layer 2 scheduling information, and calculates the first precoding weight based on the downlink channel matrix and the second precoding weight. Finally, the RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the Layer 2 scheduling information.

[0190] As can be seen, in this embodiment, the RU performs channel estimation for SRS and sends the estimated channel information to the DU. The DU performs Layer 2 scheduling based on the channel information and calculates the first and second precoding weights. The second precoding weight is then sent back to the RU via the fronthaul interface. In this process, the RU calculates the first precoding weight based on the second precoding weight obtained from the DU, reducing the complexity of the RU's precoding weight calculation. Furthermore, the fronthaul interface only transmits the second precoding weight instead of all weights, reducing the transmission traffic of the fronthaul interface. Moreover, the transmitted second precoding weight is a linear precoding weight, which further reduces transmission complexity.

[0191] Example 4: This application example provides a detailed description of the method by which the DU sends the first precoding weight and the second precoding weight to the RU through the fronthaul interface.

[0192] Referring to Figure 5A, which is a flowchart of another precoding method provided in an embodiment of this application, the method includes the following steps:

[0193] 501. The radio frequency unit RU sends SRS to the DU.

[0194] The RU receives the SRS from the UE and sends it to the DU.

[0195] 502. The Distributed Unit (DU) obtains channel information by performing channel estimation based on the SRS.

[0196] In this embodiment of the application, the DU performs channel estimation based on the SRS obtained from the RU to obtain channel information.

[0197] 503.DU performs nonlinear precoding calculations based on channel information and Layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operations in nonlinear precoding.

[0198] This step is the same as step 201 in the aforementioned embodiment, and will not be repeated here.

[0199] 504. The DU sends the first precoding weight, the second precoding weight, and the layer 2 scheduling information to the radio frequency unit RU. Correspondingly, the RU receives the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0200] Since the first precoding weight is a non-linear precoding weight (e.g., a lower triangular block matrix), and the second precoding weight can be a linear precoding weight (e.g., a unitary matrix), the fronthaul interface between DU and RU needs to support the data format for transmitting non-linear precoding weights.

[0201] For example, the DU transmits a first precoding weight and its corresponding identifier, a second precoding weight and its corresponding identifier, and Layer 2 scheduling information to the RU. The identifier corresponding to the first precoding weight indicates that the transmitted weight belongs to the first precoding weight, and the identifier corresponding to the second precoding weight indicates that the transmitted weight belongs to the second precoding weight. This allows the RU to distinguish between the first and second precoding weights. For the first precoding weight, i.e., the lower triangular matrix L of the block, its dimension in each frequency domain resource element is the number of UE data streams scheduled in that frequency domain resource element × the number of scheduled UE data streams. Therefore, the dimension of the first precoding weight in each frequency domain resource element is... Each weight corresponds to a user identifier and a user data stream identifier, where N f The total number of UE data streams scheduled on frequency domain resource unit f. For the second precoding weight, i.e., the unitary matrix Q, in each frequency domain resource unit, the dimension of the second precoding weight is the number of base station transmit antennas × the number of UE data streams scheduled on that frequency domain resource unit. Each weight corresponds to a user identifier and a user data stream identifier. The transmission time of the first precoding weight and its corresponding identifier, the second precoding weight and its corresponding identifier, and the Layer 2 scheduling information is generally short, and its time granularity can be equal to or less than the time length of a time slot.

[0202] 505. RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

[0203] The RU performs nonlinear precoding based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information. Refer to the description of step 203 in the aforementioned embodiment one, which will not be repeated here.

[0204] The communication process in steps 501 to 505 described above can also be represented by an architecture diagram. Referring to Figure 5B, which is a schematic diagram of another nonlinear precoding architecture provided in this application embodiment, the architecture includes a DU and a RU, which communicate via a fronthaul interface. The RU sends an SRS to the DU, which performs channel estimation based on the SRS to obtain channel information. Then, the DU performs Layer 2 scheduling based on the channel information to obtain Layer 2 scheduling information. Precoding calculation (LQ decomposition) is then performed based on the Layer 2 scheduling information and the channel information to obtain a first precoding weight and a second precoding weight. The fronthaul interface between the DU and RU transmits the first precoding weight, the second precoding weight, and the Layer 2 scheduling information. The RU receives the first precoding weight, the second precoding weight, and the Layer 2 scheduling information, and performs nonlinear precoding based on these weights.

[0205] As can be seen, in this embodiment, the DU performs channel estimation for SRS, performs layer 2 scheduling based on channel information, and calculates the first and second precoding weights. The first and second precoding weights are then sent to the RU via the fronthaul interface. In this process, the DU performs all precoding weight calculations, thus simplifying the computational complexity of the RU to the greatest extent possible.

[0206] Please refer to Figure 6, which is a schematic diagram of a communication device provided in an embodiment of this application. This communication device can be used to execute any of the methods in the foregoing embodiments.

[0207] As shown in Figure 6, the communication device includes a processing module 1501 and a transceiver module 1502. The processing module 1501 may be one or more processors, and the transceiver module 1502 may be a transceiver or a communication interface. This communication device can be used to implement the functions of devices such as the first communication device and the second communication device involved in any of the above method embodiments. These devices may be hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform). Optionally, the communication device may also include a storage module 1503 for storing the program code and data of the communication device.

[0208] In a first example, the communication device can be used as a distributed unit DU or a chip within the DU in the embodiments of Figures 2 to 5B, and execute the steps performed by the DU in the above method embodiments. The transceiver module 1502 is used to support communication with the radio frequency unit RU. The processing module 1501 can be used to support the execution of actions performed by the DU in the above method embodiments, excluding transmission and reception.

[0209] Specifically, the processing module 1501 is used to perform nonlinear precoding calculations based on channel information and layer 2 scheduling information to obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for the nonlinear operation of interference pre-cancellation in nonlinear precoding; the transceiver module 1502 is used to send layer 2 scheduling information to the radio frequency unit RU, and also send the first precoding weight and / or the second precoding weight.

[0210] In one feasible implementation, before performing nonlinear precoding calculations based on channel information and Layer 2 scheduling information, the transceiver module 1502 is further configured to: receive channel information from the RU; and send a first precoding weight and / or a second precoding weight to the radio frequency unit RU in the access network equipment, including: sending the first precoding weight or the second precoding weight to the RU.

[0211] In one feasible implementation, before performing nonlinear precoding calculations based on channel information and Layer 2 scheduling information, the transceiver module 1502 is further configured to: receive a channel sounding reference signal (SRS) from the RU and obtain channel information based on the SRS; and send a first precoding weight and / or a second precoding weight to the radio frequency unit (RU) in the access network equipment, including: sending the first precoding weight and the second precoding weight to the RU.

[0212] In one feasible implementation, the first precoding weight is a block lower triangular matrix, and the second precoding weight is a unitary matrix. The block lower triangular matrix and the unitary matrix are generated by LQ decomposition of the channel feature matrix of the data stream corresponding to the terminal scheduled on each frequency domain resource unit in the layer 2 scheduling information.

[0213] In a second example, the communication device can be used as the radio frequency unit RU or a chip within the RU in the embodiments of Figures 2 to 5B, and execute the steps performed by the RU in the above method embodiments. The transceiver module 1502 is used to support communication with the DU. The processing module 1501 can be used to support the execution of actions other than sending and receiving performed by the RU in the above method embodiments.

[0214] Specifically, the transceiver module 1502 is used to receive layer 2 scheduling information and obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operation of interference pre-cancellation in nonlinear precoding; the processing module 1501 is used to perform nonlinear precoding based on the first precoding weight, the second precoding weight and the layer 2 scheduling information.

[0215] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the first precoding weight from the DU; and performing matrix inversion calculation based on the channel information, layer 2 scheduling information and the first precoding weight to obtain the second precoding weight.

[0216] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the second precoding weight from the DU; and performing matrix multiplication calculation based on the channel information, layer 2 scheduling information, and the second precoding weight to obtain the first precoding weight.

[0217] In one feasible implementation, obtaining the first precoding weight and the second precoding weight includes: receiving the first precoding weight and the second precoding weight from the DU.

[0218] In one feasible implementation, the first precoding weight is a block lower triangular matrix, and the second precoding weight is a unitary matrix.

[0219] In one feasible implementation, before obtaining the first precoding weight and the second precoding weight, the transceiver module 1502 is further configured to: receive a channel sounding reference signal (SRS), obtain channel information based on the SRS, and send the channel information to the DU, wherein the channel information is used for the calculation of the first precoding weight and the second precoding weight.

[0220] In one feasible implementation, precoding is performed based on a first precoding weight and a second precoding weight, including: performing interference pre-cancellation on the data stream corresponding to the terminal scheduled on each frequency domain resource unit indicated in the Layer 2 scheduling information based on the first precoding weight to obtain the data stream vector after interference pre-cancellation; and performing filtering processing on the data stream vector based on the second precoding weight to complete the precoding.

[0221] The processing module 1501 may be a processor that can execute computer execution instructions stored in the storage module to cause the chip to perform the methods involved in any of the above embodiments.

[0222] Please refer to Figure 7, which is a simplified structural diagram of a network device provided in an embodiment of this application, and can be used as an implementation of the first communication device of this application.

[0223] The network device includes a radio frequency (RF) signal transceiver and conversion section and a baseband section 42. The RF signal transceiver and conversion section further includes a receiving module 41 and a transmitting module 43 (which can also be collectively referred to as transceiver modules). The RF signal transceiver and conversion section is mainly used for transmitting and receiving RF signals and converting RF signals to baseband signals. The baseband section 42 is mainly used for baseband processing and controlling the network device. The receiving module 41 can also be called a receiver, receiver circuit, etc., and the transmitting module 43 can also be called a transmitter, transmitter, transmitter circuit, etc. The baseband section 42 is usually the control center of the network device, and can also be called a processing module, used to execute the steps performed by the network device in any of the above methods. See the description of the relevant sections above for details. The transmitting module 43 may include an antenna and RF circuitry. The RF circuitry is mainly used for converting baseband signals to RF signals and processing RF signals. The antenna is mainly used for transmitting and receiving RF signals in the form of electromagnetic waves.

[0224] The baseband section 42 may include one or more boards, each board may include one or more processors and one or more memories. The processors are used to read and execute programs in the memories to implement baseband processing functions and control network devices. If multiple boards exist, they can be interconnected to increase processing power. As an optional implementation, multiple boards may share one or more processors, multiple boards may share one or more memories, or multiple boards may simultaneously share one or more processors.

[0225] Please refer to Figure 8, which is a schematic diagram of a RAN chip structure provided in an embodiment of this application, and can be used as another implementation of the network device of this application.

[0226] The RAN chip is divided into CU, DU, and RU. The CU is a platform that performs upper-layer L2 (data link layer) and L3 (network layer) functions. The midhaul and backhaul interfaces are used to carry traffic between the CU and DU, as well as between the CU and the core network. The DU performs L1 and some L2 functions, while the RU performs L1 (physical layer) computation and RF digital functions. The fronthaul and backhaul interfaces are used to carry traffic between the RU and DU, as well as between the CU and DU. An integrated DU includes the functions of both the DU and RU.

[0227] The CU / DU hardware includes a chassis platform, motherboard, peripherals, and cooling system. The motherboard contains processing units, memory, internal I / O interfaces, and external connection ports. Its hardware accelerator is designed with interfaces, and hardware functional components include: storage for software, hardware, and system debugging interfaces, and a single-board management controller.

[0228] DU systems are typically implemented using multi-core processors and one or more hardware accelerators. Parts of the DU protocol stack can be implemented in software running on the multi-core processor, while computationally intensive L1 and L2 functions can be offloaded to FPGA / GPU-based hardware accelerators; alternatively, all L1 functions can be offloaded to FPGA / GPU-based hardware accelerators, while other protocol stack components are implemented in software running on the processor; or the entire protocol stack can be implemented in software running on the processor. Hardware accelerators support interconnection with x86 or non-x86 processors. Similarly, accelerators have multi-channel PCIe interfaces pointing to the CPU and external connections via GbE.

[0229] The RU comprises three parts: the OPU (O-RAN Processing Unit), which receives eCPRI frames from the O-RAN fronthaul and performs fronthaul interface, lowest-level L1 (coding, scrambling, modulation, layer mapping, precoding), synchronization, beamforming, and resource unit mapping. The OPU can be implemented as a CPU, FPGA, or ASIC. The DPU (O-RU Digital Processing Unit) performs synchronization, DDC (digital downconversion in UL), DUC (digital upconversion in DL), CFR, and DPD, improving power amplifier efficiency by reducing PAPR / ACLR at the RF front-end; the DPU can be implemented as an FPGA or ASIC. The O-RU's RF processing unit includes a transceiver module, up / down converters, power amplifiers (PA), low-noise amplifiers (LNA), and Tx / Rx filters. All conversions between the analog and digital domains (DAC and ADC) (e.g., RF sampling, frequency conversion using RF, IF, and LO mixing during up-conversion and down-conversion) are performed within the transceiver module. Note that physical and logical partitions within the RF processing unit do not require specific boundaries.

[0230] Please refer to Figure 9, which is a simplified structural diagram of a UE provided in an embodiment of this application, as one implementation of the UE in this application.

[0231] For ease of understanding and illustration, Figure 9 uses a mobile phone as an example of the UE. As shown in Figure 9, the UE includes at least one processor, and may also include radio frequency (RF) circuitry, an antenna, and input / output devices. The processor can be used to process communication protocols and communication data, as well as to control the UE, execute software programs, and process data from those programs. The UE may also include a memory, primarily used to store software programs and data. These programs can be loaded into the memory at the time of manufacture or added later when needed. The RF circuitry is mainly used for converting baseband signals to RF signals and processing RF signals. The antenna is mainly used for transmitting and receiving RF signals in the form of electromagnetic waves. Input / output devices, such as touchscreens, displays, and keyboards, are mainly used to receive user input data and output data to the user. It should be noted that some types of UEs may not have input / output devices.

[0232] When a signal needs to be transmitted, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit then processes the baseband signal and transmits it outward as an electromagnetic wave through the antenna. When data is sent to the UE, the RF circuit receives the RF signal through the antenna, converts it into a baseband signal, and outputs it to the processor. The processor converts the baseband signal back into data and processes it. For ease of explanation, Figure 9 only shows one memory and one processor. In actual UE products, there may be one or more processors and one or more memories. Memory can also be called storage medium or storage device, etc. Memory can be set up independently of the processor or integrated with the processor; this embodiment does not limit this.

[0233] In this embodiment, the antenna and radio frequency circuit with transceiver functions can be regarded as the receiving unit and transmitting unit of the UE (or collectively referred to as the transceiver unit), and the processor with processing functions can be regarded as the processing unit of the UE. As shown in Figure 9, the UE includes a receiving module 31, a processing module 32, and a transmitting module 33. The receiving module 31 can also be referred to as a receiver, receiver circuit, etc., and the transmitting module 33 can also be referred to as a transmitter, transmitter, transmitter circuit, etc. The processing module 32 can also be referred to as a processor, processing board, processing device, etc.

[0234] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0235] Optionally, the memory may also store data. The processor and memory may be configured separately or integrated together. The memory may be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it may be volatile memory, such as random-access memory (RAM). In the embodiments of this application, the processor may also be flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art.

[0236] Optionally, the UE may include instructions (sometimes referred to as code or program) that can be executed on the processor.

[0237] Optionally, the UE may also include a transceiver and an antenna. The transceiver may be referred to as a transceiver unit, transceiver module, transceiver, transceiver circuit, transceiver, input / output interface, etc., and is used to realize the UE's transmission and reception functions through the antenna.

[0238] This application provides a communication system, which includes the first communication device and the second communication device described above.

[0239] This application provides a computer-readable storage medium storing computer instructions that, when executed, cause the computer to perform the method described in any of the above methods.

[0240] This application provides a computer program product, which includes computer program code. When the computer program code is run, it causes the computer to perform the method described in any of the above methods.

[0241] This application provides a chip coupled to a memory for reading and executing program instructions in the memory, so that the device containing the chip implements the method described in any of the above methods.

[0242] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not described in detail in a particular embodiment can be found in the relevant descriptions of other embodiments. It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0243] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above 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 devices or units may be electrical or other forms.

[0244] The units described above 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.

[0245] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A precoding method, characterized in that, Applied to a distributed unit (DU), the method includes: Based on channel information and layer 2 scheduling information, nonlinear precoding is calculated to obtain a first precoding weight and a second precoding weight. The first precoding weight is used for the nonlinear operation of interference pre-cancellation in nonlinear precoding. Layer 2 scheduling information is sent to the radio frequency unit RU, and the first precoding weight and / or the second precoding weight are also sent.

2. The method according to claim 1, characterized in that, Before performing nonlinear precoding calculations based on channel information and layer 2 scheduling information, the method further includes: Receive channel information from the RU; Sending the first precoding weight and / or the second precoding weight to the radio frequency unit (RU) in the access network device includes: Send the first precoding weight or the second precoding weight to the RU.

3. The method according to claim 1, characterized in that, Before performing nonlinear precoding calculations based on channel information and layer 2 scheduling information, the method further includes: Receive the channel sounding reference signal (SRS) from the RU, and obtain the channel information based on the SRS; Sending the first precoding weight and / or the second precoding weight to the radio frequency unit (RU) in the access network device includes: The first precoding weight and the second precoding weight are sent to the RU.

4. The method according to any one of claims 1-3, characterized in that, The first precoding weight is a lower triangular matrix of blocks, and the second precoding weight is a unitary matrix. The lower triangular matrix of blocks and the unitary matrix are generated by LQ decomposition of the channel feature matrix of the data stream corresponding to the terminal scheduled on each frequency domain resource unit in the layer 2 scheduling information.

5. A precoding method, characterized in that, Applied to a radio frequency unit RU, the method includes: Receive Layer 2 scheduling information and obtain a first precoding weight and a second precoding weight, wherein the first precoding weight is used for nonlinear operation of interference pre-cancellation in nonlinear precoding; Nonlinear precoding is performed based on the first precoding weight, the second precoding weight, and the layer 2 scheduling information.

6. The method according to claim 5, characterized in that, The process of obtaining the first precoding weight and the second precoding weight includes: Receive the first precoding weight from the DU; The second precoding weight is obtained by matrix inversion based on the channel information, layer 2 scheduling information, and the first precoding weight.

7. The method according to claim 5, characterized in that, The process of obtaining the first precoding weight and the second precoding weight includes: Receive the second precoding weight from the DU; The first precoding weight is obtained by matrix multiplication based on the channel information, the layer 2 scheduling information, and the second precoding weight.

8. The method according to claim 5, characterized in that, The process of obtaining the first precoding weight and the second precoding weight includes: Receive the first precoding weight and the second precoding weight from DU.

9. The method according to any one of claims 5-8, characterized in that, The first precoding weight is a lower triangular matrix of blocks, and the second precoding weight is a unitary matrix.

10. The method according to any one of claims 5-7, characterized in that, Before obtaining the first precoding weight and the second precoding weight, the method further includes: Receive a channel sounding reference signal (SRS) and obtain the channel information based on the SRS; The channel information is sent to the DU, and the channel information is used to calculate the first precoding weight and the second precoding weight.

11. The method according to any one of claims 5-10, characterized in that, The precoding based on the first precoding weight and the second precoding weight includes: Based on the first precoding weight, interference pre-cancellation is performed on the data stream corresponding to the terminal scheduled on each frequency domain resource unit indicated in the layer 2 scheduling information to obtain the data stream vector after interference pre-cancellation; The data stream vector is filtered based on the second precoding weights to complete the precoding.

12. A communication device, characterized in that, Used to implement the method as described in any one of claims 1 to 4.

13. A communication device, characterized in that, Used to implement the method as described in any one of claims 5 to 11.

14. The apparatus according to claim 12 or 13, characterized in that, The device is a network device or a chip in a network device.

15. A communication device, characterized in that, The communication device includes at least one processor coupled to a memory; The at least one processor is configured to execute a computer program or instructions stored in the memory, such that the method as described in any one of claims 1 to 4 is implemented, or the method as described in any one of claims 5 to 11 is implemented.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, causes the method as described in any one of claims 1 to 4 to be implemented, or causes the method as described in any one of claims 5 to 11 to be implemented.

17. A computer program, characterized in that, When the computer program is run, it causes the method as described in any one of claims 1 to 4 to be implemented, or causes the method as described in any one of claims 5 to 11 to be implemented.

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