Methods and network nodes in wireless communication systems

Abstract

A method and network node in a wireless communication system are disclosed. The method includes: receiving first information related to the second network node supporting probe reference signal beamforming (SRS-BF) from a second network node; and sending a configuration message for demodulation reference signal beamforming (DMRS-BF) to the second network node, the configuration message including first UE-related configuration information corresponding to DMRS-BF and second UE-related configuration information corresponding to SRS-BF.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and more specifically, to a method and network node in a wireless communication system. Background Technology

[0002] To meet the increased demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or near-5G communication systems. Therefore, 5G or near-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] Wireless communication is one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services surpassed 5 billion and continues to grow rapidly. The demand for wireless data services is growing rapidly due to the increasing prevalence of smartphones and other mobile data devices (such as tablets, laptops, netbooks, e-book readers, and machine-type devices) among consumers and businesses. To meet the rapid growth of mobile data services and support new applications and deployments, improving the efficiency and coverage of wireless interfaces is crucial.

[0004] 5G (5th Generation mobile communication technology) has been gradually standardized, with its three main application scenarios including Ultra-Reliable and Low Latency Communication (URLLC), Enhanced Mobile Broadband (EMBB), and Massive Machine Type Communication (mMTC). However, with the application and development of 5G, more and more devices and mobile data are connecting to 5G systems, and the Radio Access Network (RAN) is facing problems such as increased traffic volume, huge investment costs, and insufficient flexibility. To address these issues, operators hope to achieve faster innovation and greater flexibility, reduce equipment costs, and achieve higher performance by standardizing third-party equipment.

[0005] In this context, the O-RAN (Open Radio Access Network) standard emerged. O-RAN allows interoperability between network equipment from different vendors, with more open standardized interfaces and more flexible functions. Furthermore, the introduction of machine learning and artificial intelligence will bring new opportunities to O-RAN, accelerating innovation. Open and intelligent radio access networks help reduce equipment costs, stimulate innovation, and facilitate faster time-to-market for applications in various new fields. Summary of the Invention

[0006] According to embodiments of this disclosure, a method performed by a first network node in a wireless communication system is provided, comprising: receiving first information related to the second network node supporting probe reference signal beamforming (SRS-BF) from a second network node; and sending a configuration message for demodulation reference signal beamforming (DMRS-BF) to the second network node, wherein the configuration message includes first UE-related configuration information corresponding to the DMRS-BF and second UE-related configuration information corresponding to the SRS-BF.

[0007] In this implementation, sending a DMRS-BF configuration message to the second network node includes: when SRS-BF can be applied to DMRS-BF, sending a DMRS-BF configuration message to the second network node, wherein the configuration message includes configuration information related to the first UE and configuration information related to the second UE.

[0008] In this implementation, the first UE-related configuration information is carried in the first segment extension of the configuration message; the second UE-related configuration information is carried in the second segment extension of the configuration message corresponding to the first segment extension.

[0009] In the implementation, the first segmented extension includes at least one first extension field, and the second segmented extension includes at least one second extension field. The first extension field that includes the first UE-related configuration information corresponds to the second extension field that includes the second UE-related configuration information.

[0010] In this implementation, the first information includes: the identification information of the second segmented extension.

[0011] In an implementation, the second segmentation extension includes at least one of the following: UE index-related information; antenna port-related information.

[0012] In an implementation, the antenna port related information includes at least one of the following: at least one antenna port index; the number of antenna ports; and the index of the antenna port with the largest index value.

[0013] In this implementation, the DMRS-BF and the SRS-BF correspond to the same UE; the second UE-related configuration information includes: indication information indicating that the DMRS-BF and the SRS-BF correspond to the same UE.

[0014] In one implementation, receiving first information related to the second network node's support for SRS-BF from the second network node includes: receiving a management plane message from the second network node, wherein the management plane message includes first information related to the second network node's support for SRS-BF.

[0015] In this implementation, sending a DMRS-BF configuration message to the second network node includes sending a control plane message to the second network node, wherein the control plane message includes the DMRS-BF configuration message.

[0016] In the implementation, sending a DMRS-BF configuration message to the second network node includes: when the scheduling and processing of the Physical Uplink Shared Channel (PUSCH) belong to the same SRS channel information reporting period, sending a DMRS-BF configuration message to the second network node.

[0017] In an implementation, the method further includes: sending SRS configuration information to the second network node, the SRS configuration information including at least one of the following: SRS configuration period, UE priority information; receiving channel information from the second network node, the channel information being determined by the second network node based on the SRS configuration information.

[0018] According to embodiments of this disclosure, a method executed by a second network node in a wireless communication system is provided, comprising: sending first information related to the second network node supporting probe reference signal beamforming (SRS-BF) to a first network node; and receiving a configuration message of demodulation reference signal beamforming (DMRS-BF) from the first network node, wherein the configuration message includes first UE-related configuration information corresponding to the DMRS-BF and second UE-related configuration information corresponding to the SRS-BF.

[0019] In this implementation, receiving a DMRS-BF configuration message from the first network node includes: when SRS-BF can be applied to DMRS-BF, receiving a DMRS-BF configuration message from the first network node, wherein the configuration message includes configuration information related to the first UE and configuration information related to the second UE.

[0020] In this implementation, the first UE-related configuration information is carried in the first segment extension of the configuration message; the second UE-related configuration information is carried in the second segment extension of the configuration message corresponding to the first segment extension.

[0021] In the implementation, the first segmented extension includes at least one first extension field, and the second segmented extension includes at least one second extension field. The first extension field that includes the first UE-related configuration information corresponds to the second extension field that includes the second UE-related configuration information.

[0022] In this implementation, the first information includes: the identification information of the second segmented extension.

[0023] In an implementation, the second segmentation extension includes at least one of the following: UE index-related information; antenna port-related information.

[0024] In an implementation, the antenna port related information includes at least one of the following: at least one antenna port index; the number of antenna ports; and the index of the antenna port with the largest index value.

[0025] In this implementation, the DMRS-BF and the SRS-BF correspond to the same UE; the second UE-related configuration information includes: indication information indicating that the DMRS-BF and the SRS-BF correspond to the same UE.

[0026] In one implementation, sending first information related to the second network node's support for SRS-BF to the first network node includes: sending a management plane message to the first network node, wherein the management plane message includes the first information related to the second network node's support for SRS-BF.

[0027] In one implementation, receiving a DMRS-BF configuration message from a first network node includes receiving a control plane message from the first network node, wherein the control plane message includes the DMRS-BF configuration message.

[0028] In the implementation, receiving the DMRS-BF configuration message from the first network node includes: receiving the DMRS-BF configuration message from the first network node when the scheduling and processing of the Physical Uplink Shared Channel (PUSCH) belong to the same SRS channel information reporting period.

[0029] In an implementation, the method further includes: receiving SRS configuration information from the first network node, wherein the SRS configuration information includes at least one of the following: SRS configuration period and UE priority information; determining channel information based on the SRS configuration information; and sending the channel information to the first network node.

[0030] In an implementation, the method further includes: executing the DMRS-BF based on the configuration message of the DMRS-BF.

[0031] According to embodiments of this disclosure, a method performed by a first network node in a wireless communication system is provided, comprising: determining whether a probe reference signal beamforming (SRS-BF) is used to perform demodulation reference signal beamforming (DMRS-BF); if the SRS-BF is used to perform the DMRS-BF, then sending first information including a first user equipment identifier of the DMRS-BF and second information including a second user equipment identifier of the SRS-BF to a second network node, wherein the first user equipment identifier and the second user equipment identifier indicate the same user equipment (UE).

[0032] In one embodiment, the method further includes: receiving third information from the second network node related to whether the second network node supports the SRS-BF and the DMRS-BF; wherein determining whether the SRS-BF is used to execute the DMRS-BF includes: determining whether the SRS-BF is used to execute the DMRS-BF based on the third information received from the second network node related to whether the second network node supports the SRS-BF and the DMRS-BF.

[0033] In an implementation, the third information includes fourth information related to the number of bits of the user index of the second user equipment identifier and fifth information related to whether segmented extension of the second user equipment identifier is supported.

[0034] In an implementation, the segmented expansion of the second user equipment identifier includes at least one of the following: a plurality of second user equipment identifiers, wherein the plurality of second user equipment identifiers include the same user index and different antenna port indexes; a user index and a plurality of different antenna port indexes; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the index of any one antenna port; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the index of the largest antenna port; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the number of antenna ports.

[0035] In one implementation, receiving third information related to whether the second network node supports the SRS-BF and the DMRS-BF from the second network node includes: receiving a management plane message including a list of segment extensions from the second network node; wherein the method further includes: determining whether the second network node supports the SRS-BF and the DMRS-BF based on whether the list of segment extensions in the management plane message includes segment extensions related to the transmission of the second user equipment identifier.

[0036] In one implementation, sending first information including the first user equipment identifier of the DMRS-BF and second information including the second user equipment identifier of the SRS-BF to the second network node includes: sending the first information including the first user equipment identifier of the DMRS-BF and the second information including the second user equipment identifier of the SRS-BF to the second network node via control plane messages.

[0037] In an implementation, at least one user index in the segmented extension of the second user equipment identifier corresponds one-to-one with at least one user index in the segmented extension of the first user equipment identifier.

[0038] According to embodiments of this disclosure, a method performed by a second network node in a wireless communication system is provided, comprising: receiving from a first network node first information including a first user equipment identifier comprising demodulation reference signal beamforming (DMRS-BF) and second information including a second user equipment identifier comprising detection reference signal beamforming (SRS-BF), wherein the first user equipment identifier and the second user equipment identifier indicate the same user equipment (UE); and performing the DMRS-BF based on the SRS-BF according to the first user equipment identifier and the second user equipment identifier.

[0039] In an implementation, the method further includes: sending third information to the first network node related to whether the second network node supports the SRS-BF and the DMRS-BF, wherein the third information is used to determine whether the SRS-BF is used for the DMRS-BF.

[0040] In an implementation, the third information includes fourth information related to the number of bits of the user index of the second user equipment identifier and fifth information related to whether segmented extension of the second user equipment identifier is supported.

[0041] In an implementation, the segmented expansion of the second user equipment identifier includes at least one of the following: a plurality of second user equipment identifiers, wherein the plurality of second user equipment identifiers include the same user index and different antenna port indexes; a user index and a plurality of different antenna port indexes; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the index of any one antenna port; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the index of the largest antenna port; a second user equipment identifier wherein the least significant bit of the second user equipment identifier indicates the number of antenna ports.

[0042] In one implementation, sending third information related to whether the second network node supports the SRS-BF and the DMRS-BF to the first network node includes sending a management plane message to the first network node including a list of segmented extensions, wherein the list of segmented extensions is used to determine whether the second network node supports the SRS-BF and the DMRS-BF.

[0043] In one implementation, receiving first information including a first user equipment identifier of DMRS-BF and second information including a second user equipment identifier of SRS-BF from a first network node includes: receiving the first information including the first user equipment identifier of DMRS-BF and the second information including the second user equipment identifier of SRS-BF from the first network node via control plane messages.

[0044] In an implementation, at least one user index in the segmented extension of the second user equipment identifier corresponds one-to-one with at least one user index in the segmented extension of the first user equipment identifier.

[0045] According to embodiments of this disclosure, a method performed by a first network node in a wireless communication system is provided, comprising: determining whether a probe reference signal beamforming (SRS-BF) is used to perform demodulation reference signal beamforming (DMRS-BF); if the SRS-BF is used to perform the DMRS-BF, sending first information including a first user equipment identifier of the DMRS-BF and first indication information to a second network node, wherein the first indication information is used to instruct the second network node to use the same user index as the user index of the first user equipment identifier for the SRS-BF.

[0046] In one embodiment, the method further includes: receiving third information from the second network node related to whether the second network node supports the SRS-BF and the DMRS-BF; wherein determining whether the SRS-BF is used to execute the DMRS-BF includes: determining whether the SRS-BF is used to execute the DMRS-BF based on receiving third information related to the second network node supporting the SRS-BF and the DMRS-BF from the second network node via management plane messages.

[0047] In an implementation, the third information includes fourth information related to the number of bits of the user index of the first user equipment identifier and the second user equipment identifier.

[0048] In one implementation, sending first information including the first user equipment identifier of the DMRS-BF and first indication information to the second network node includes: sending the first information including the first user equipment identifier of the DMRS-BF and the first indication information to the second network node via control plane messages.

[0049] According to embodiments of this disclosure, a method performed by a second network node in a wireless communication system is provided, comprising: receiving from a first network node first information including a first user equipment identifier of a demodulation reference signal beamforming (DMRS-BF) and first indication information, wherein the first indication information is used to instruct the second network node to use a user index identical to the user index of the first user equipment identifier for probe reference signal beamforming (SRS-BF); and performing the DMRS-BF based on the user index of the DMRS-BF and the user index of the SRS-BF.

[0050] In an implementation, the method further includes: sending third information related to whether the second network node supports the SRS-BF and the DMRS-BF to the first network node via a management plane message.

[0051] In an implementation, the third information includes the first user equipment identifier and fourth information related to the number of bits of the user index of the second user equipment identifier.

[0052] In one implementation, receiving first information including a first user equipment identifier of DMRS-BF and first indication information from a first network node includes: receiving the first information including the first user equipment identifier of DMRS-BF and the first indication information from the first network node via control plane messages.

[0053] According to embodiments of this disclosure, a network node in a wireless communication system is provided, comprising: a transceiver; and a controller coupled to the transceiver and configured to perform the aforementioned method. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure. In the drawings:

[0055] Figure 1 A diagram illustrating a reference architecture for an O-RAN base station according to various embodiments of the present disclosure is shown;

[0056] Figure 2aExamples of processing flows for transmitting and receiving downlink air interface data in O-RAN according to various embodiments of the present disclosure are shown;

[0057] Figure 2b Examples of processing flows for transmitting and receiving uplink air interface data in O-RAN according to various embodiments of the present disclosure are shown;

[0058] Figure 3 A schematic diagram of the control plane message transport layer structure according to various embodiments of the present disclosure is shown;

[0059] Figures 4-7 Flowcharts of methods performed by a first network node according to various embodiments of the present disclosure are shown;

[0060] Figures 8-9 Flowcharts illustrating methods performed by a second network node according to various embodiments of the present disclosure are shown;

[0061] Figure 10 A flowchart is shown illustrating a method for resolving channel information asynchrony according to various embodiments of the present disclosure;

[0062] Figure 11 A block diagram of a network node according to various embodiments of the present disclosure is shown. Detailed Implementation

[0063] The following description, with reference to the accompanying drawings, is provided to aid in a thorough understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. This description includes various specific details to aid understanding but should be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0064] The terms and wording used in the following description and claims are not limited to their dictionary meanings, but are merely used by the inventors to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is for illustrative purposes only and not for limiting the purpose of this disclosure as defined in the appended claims and their equivalents.

[0065] It should be understood that the singular forms of “one,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, the reference to “component surface” includes one or more such surfaces.

[0066] The terms “comprising” or “may include” refer to the presence of a corresponding disclosed function, operation, or component that may be used in the various embodiments of this disclosure, rather than limiting the presence of one or more additional functions, operations, or features. Furthermore, the terms “comprising” or “having” may be interpreted as indicating certain characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof, but should not be construed as excluding the possibility of the presence of one or more other characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof.

[0067] The term "or" as used in the various embodiments of this disclosure includes any of the listed terms and all combinations thereof. For example, "A or B" may include A, may include B, or may include both A and B.

[0068] Unless otherwise defined, all terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of those skilled in the art as described herein. Common terms as defined in dictionaries are to be interpreted as having a meaning consistent with the context in the relevant technical field and should not be interpreted ideally or overly formally unless expressly defined in this disclosure.

[0069] The accompanying drawings and various embodiments used to illustrate the principles of this disclosure in this patent document are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or apparatus.

[0070] In the basic architecture of O-RAN, the fronthaul interface (FH IF) between O-DU (O-RAN Distributed Unit) and O-RU (O-RAN Radio Unit) is an open network. With limited bandwidth resources, strict requirements must be placed on transmission latency, and effectively reducing the load on the fronthaul interface is a key consideration and optimization aspect of O-RAN. Currently, optimization of O-RAN fronthaul load mainly involves using various compression algorithms on the user plane to reduce the number of bits required to transmit the same data, and on the control plane, using various extensions to reduce the number of bits for transmitted control messages. However, existing implementations do not consider the cyclical transmission characteristics and repetitive transmission characteristics of 5G. Optimizing the fronthaul interface based on these transmission characteristics can reduce the number of transmissions of user plane and control plane messages, thereby further reducing the fronthaul load and improving transmission reliability and stability.

[0071] The base station reference architecture in O-RAN is as follows: Figure 1As shown in the diagram, the base station can be a gNB (next generation NodeB, NR base station) supporting the 5G NR (New Radio) standard, or an eNB (evolved NodeB, LTE base station) supporting 4G LTE (Long Term Evolution). The reference architectures of gNB and eNB are slightly different, but this does not affect the content of this disclosure; therefore, no distinction is made between gNB and eNB. This disclosure also does not involve other functional entities outside the base station in O-RAN and their interfaces with the base station, and therefore they are not shown in the diagram. The specific modules in the O-RAN reference architecture will be described below; irrelevant modules will not be described in detail.

[0072] 101 O-CU (O-RAN Central Unit): A logical node comprising O-CU-CP (O-RAN Central Unit-Control Plane) and O-CU-UP (O-RAN Central Unit-User Plane). O-CU-CP is a logical node containing the control plane portions of RRC (Radio Resource Control) and PDCP (Packet Data Convergence Protocol), while O-CU-UP is a logical node containing the user plane portions of SDAP (Service Data Adaptation Protocol) and PDCP.

[0073] 102 O-DU (O-RAN Distributed Unit): is a logical node based on lower layer functional split and containing RLC (Radio Link Control), MAC (Media Access Control), and High-PHY (High Physical layer).

[0074] 102-1 MAC: A 3GPP functional layer primarily responsible for mapping logical channels and transport channels. It multiplexes MAC SDUs (Service Data Units) from one or more different logical channels onto TBs (Transport Blocks) for transmission to the physical layer on the transport channel. It also demultiplexes MAC SDUs from transport channel TBs onto one or more different logical channels. Furthermore, it supports scheduling information reporting, such as error correction via HARQ (Hybrid Automatic Repeat reQuest) and data transmission according to logical channel priority.

[0075] 102-2 High-PHY: After the 3GPP functional layer physical layer is split, the physical layer processing functions on the fronthaul interface O-DU side include forward error correction coding / decoding, channel estimation, modulation / demodulation, scrambling / descrambling, etc.

[0076] 102-3 O-DU CUS-Plane Application (O-DU Control, User, SynchronizationPlane Application, referred to as O-DU application in this disclosure): An O-DU logical function responsible for creating and sending, or receiving and processing, C-Plane (Control-Plane), U-Plane (User-Plane), and S-Plane (Synchronization-Plane) messages on the fronthaul interface to and from the O-RU (O-RAN Radio Unit). The control plane specifically refers to real-time control information between the O-DU and O-RU. Control plane messages carry information related to controlling user plane messages (e.g., scheduling and coordination information required for data transmission and beamforming). User plane messages carry time-frequency domain I / Q (In-phase / Quadrature) data transmitted between the O-DU and O-RU. Synchronization plane messages are used to achieve timing and time-frequency synchronization between the O-DU and O-RU. CUS-Plane (C-Plane, U-Plane, and S-Plane) is used for real-time transmission between the O-DU and O-RU fronthaul interfaces based on data scheduling.

[0077] 102-4 O-DU M-Plane (O-DU Management Plane): O-DU logical functions refer to the non-real-time management operations between O-DU and O-RU. Based on NETCONF / YANG (Network Configuration / YetAnother Next Generation, Network Configuration Protocol / YANG Data Modeling Language), it performs initialization, software management, configuration management, performance management, fault management, file management, etc. on O-RU. The configuration of M-Plane (Management Plane) is usually relatively static.

[0078] 103 OFH I / F (O-RAN Open Fronthaul interface): Fronthaul is the logical link connecting O-DU and O-RU, responsible for transmitting information from the control plane, user plane, synchronization plane, and pipeline. FH IF includes the CUS-Plane and M-Plane interfaces, and is based on eCPRI (enhanced Common Public Radio Interface) or IEEE (Institute of Electrical and Electronics Engineers) interfaces.

[0079] 104 O-RU (O-RAN Radio Unit): is a logical node based on lowerlayer functional split, carrying Low-PHY (Low Physical layer) and RF (Radio Frequency) processing.

[0080] 104-1 O-RU CUS-Plane Application (O-RU Control, User, SynchronizationPlane Application, O-RU control plane / user plane / synchronization plane application, referred to as O-RU application in this disclosure): O-RU logical function, responsible for sending or receiving messages from O-DU on the fronthaul interface and processing C-Plane, U-Plane and S-Plane messages.

[0081] 104-2 Low-PHY: After the 3GPP functional layer physical layer is split, the functions processed on the fronthaul interface O-RU side are responsible for FFT / IFFT (Fast Fourier Transform / Invert Fast Fourier Transform), analog beamforming, digital beamforming, digital-to-analog / analog-to-digital conversion, and other functions.

[0082] 104-3 O-RU M-Plane (O-RU Management Plane) is the logical function of O-RU. It is managed by O-DU M-Plane and reports capabilities to O-DU during the initialization phase to inform O-DU which optional capabilities the O-RU supports.

[0083] In the method of real-time control of air interface data transmission and reception based on control plane messages, there are different processing for uplink and downlink.

[0084] Figure 2a The processing flow for downlink data is as follows:

[0085] Step 201 is downlink scheduling, which is performed in the O-DU, specifically in the 102-1 MAC scheduler. After completing the downlink scheduling, the MAC scheduler sends the downlink scheduling results to the High-PHY for modulation and coding processing, and also sends the scheduling results to the 102-3 O-DU application for the creation of control plane and user plane messages. The smallest granularity of the downlink scheduling results is the OFDM symbol (Orthogonal Frequency Division Multiplexing symbol), and the smallest granularity of the frequency domain is the RE (Resource Element, which occupies one OFDM symbol in the time domain and one subcarrier in the frequency domain). The scheduling results include, but are not limited to, the time and frequency domain resource allocation information of PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and CSI-RS (Channel State Information - Reference Signal), beam index, etc.

[0086] Step 202 involves the transmission and reception of downlink control plane messages, performed in both the O-DU and O-RU, specifically in the 102-3 O-DU application, 103 FH I / F, and 104-1 O-RU application. Based on the scheduling results from step 201, the O-DU application creates a control plane message for controlling downlink air interface data transmission and sends it to the O-RU application via FH I / F. This control plane message primarily indicates OFDM symbols, PRBs (Physical Resource Blocks, composed of REs), REs and beam indices, IFFT parameters, and other information. The O-RU application receives the control plane message and extracts various fields from the transport and application layers.

[0087] Step 203 involves the transmission and reception of downlink user plane messages, performed in the O-DU and O-RU, specifically in the 102-3 O-DU application, the 103 FH I / F application, and the 104-1 O-RU application. The O-DU application creates downlink user plane messages from the modulated and coded I / Q data output by the High-PHY and sends them to the O-RU application via FH I / F. These user plane messages primarily carry the specified OFDM symbols and the I / Q data carried on each RE in the PRB. The O-RU application receives the user plane messages and obtains the various field information and I / Q data from the transport and application layers.

[0088] Step 204 involves control plane / user plane message coupling, performed within the O-RU, specifically in the 104-1 O-RU application. Since control plane messages and user plane messages are transmitted separately, it is necessary to couple the section descriptions in the control plane information with the data sections in the user plane messages. The basic coupling method is section index-based coupling. Furthermore, to reduce the number of section descriptions in the control plane messages, coupling methods based on time-frequency resources and priority-based time-frequency resource coupling have been proposed.

[0089] Step 205 controls the transmission of downlink air interface data, which is performed in the O-RU, specifically in the 104-1 O-RU application and the 104-2 Low-PHY. After the O-RU application completes coupling, it submits the coupled segment description and data segments to the Low-PHY. The Low-PHY processes the coupled segment description and data segments, performing digital beamforming, IFFT (Fast Fourier Transform), and analog beamforming on the downlink data segments according to the control information indicated in the segment description.

[0090] Figure 2b The process for processing upstream data is as follows:

[0091] Step 206 is uplink scheduling, which is performed in the O-DU, specifically in the 102-1 MAC scheduler. After completing the uplink scheduling, the MAC scheduler sends the uplink scheduling results to the High-PHY for decoding and demodulation processing after receiving user plane data from the O-RU. It also sends the scheduling results to the O-DU application for creating control plane messages. The smallest granularity of the uplink scheduling results is OFDM symbols, and the smallest granularity of the frequency domain is RE. The scheduling results include, but are not limited to, time-domain and frequency-domain resource allocation information for PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), SRS (Sounding Reference Signal), PRACH (Physical Random Access Channel), and DMRS (Demodulation Reference Signal), as well as beam indices.

[0092] Step 207 involves the transmission and reception of uplink control plane messages, performed in both the O-DU and O-RU, specifically in the 102-3 O-DU application, 103 FH I / F, and 104-1 O-RU application. Based on the scheduling result from step 206, the O-DU application creates a control plane message for controlling uplink air interface data reception and sends it to the O-RU application via FH I / F. This control plane message primarily indicates information such as OFDM symbols, PRBs, REs, beam indices, and FFT parameters. The O-RU application receives the control plane message and extracts various field information from the transport and application layers.

[0093] Step 208 controls the reception of uplink air interface data, which is performed in the O-RU, specifically in the 104-1 O-RU application and 104-2 Low-PHY. The O-RU application instructs the Low-PHY on the control information carried in the segment description extracted from the control plane message. The Low-PHY processes the uplink air interface data according to the control information, performing analog beamforming, FFT, digital beamforming, etc., and then delivers the processed I / Q data to the O-RU application.

[0094] Step 209 involves the transmission and reception of uplink user plane messages, performed in the O-RU and O-DU, specifically in the 104-1 O-RU application, 103 FH I / F, and 102-3 O-DU application. The O-RU application creates uplink user plane messages from the I / Q data output from the Low-PHY and sends them to the O-DU application via FH I / F. These user plane messages primarily carry the I / Q data carried on each RE in the specified OFDM symbol and PRB. The O-DU application receives the user plane messages, obtains the I / Q data carried on each RE in the specified OFDM symbol and PRB from the user plane messages, and then delivers the I / Q data to the High-PHY for subsequent decoding and demodulation processing.

[0095] Figure 2a and Figure 2b Each control plane message belongs to a specific endpoint (which can be the corresponding downlink transmitting endpoint low-level-tx-endpoint or the corresponding uplink receiving endpoint low-level-rx-endpoint). Each endpoint is assigned a unique eAxC Id (extended Antenna-CarrierIdentifier), which is carried in the transport layer header of both control plane and user plane messages and is used by O-RU and O-DU to distinguish which endpoint the message belongs to.

[0096] The eAxC ID is divided into ecpriRtcid and ecpriPcid. ecpriRtcid (real-time controldata identifier) ​​is used to identify the data stream related to control plane messages. The transport layer structure in control plane messages is as follows: Figure 3 As shown, where,

[0097] 301 Transport Header: This can be an Enhanced Common Radio Interface (eCPRI) header or an Ethernet Radio (ROE) header, including appropriate fields to indicate the message type, such as eAxC ID.

[0098] 302 Application Layer: Includes the necessary fields for control and synchronization, i.e., the transport layer payload.

[0099] 303 Common Radio Application Header: Contains information such as data direction, payload version, filter index, frame number, subframe number, slot ID, start symbol ID, number of sections, and section type.

[0100] 304 Section Description: Describes control information, containing information used to control the sending or receiving of user plane messages. A single control plane message can contain multiple section descriptions.

[0101] 305 Section Header: Contains the section index (sectionId), symbol increment marker (symInc), number of symbols (numSymbol), and frequency domain resource information (such as: the starting PRB of the section description (startPrbc), the number of consecutive PRBs in the section description (numPrbc), and the number of symbols (numSymbol)), beam index (beamId), extension identifier (ef), etc.

[0102] 306 Section extension describes control information in addition to the information contained in the section header. A section description can contain multiple section extensions. If the extension identifier ef has a value of 1, it indicates that there are other section extensions following this section extension.

[0103] The beamforming methods currently supported by O-RAN include: PDBF (Predefined-beam beamforming), WDBF (Weight-based dynamic beamforming), ABBF (Attribute-based dynamic beamforming), CIBF (Channel-information-based beamforming), and DMRS-BF (DMRS-based beamforming).

[0104] In DMRS-BF, the O-DU provides a DMRS configuration description for the PUSCH. The O-RU performs channel estimation based on the received DMRS, calculates beamforming weights from the DMRS data with or without an equalization function, and applies these weights to the PUSCH data and optional DMRS data. Since beam indexing is not used in this method, the use of beam indexing is irrelevant to this beamforming method. This beamforming method is only applicable to NR PUSCH. Currently, DMRS-based beamforming has been applied to the O-RU to reduce fronthaul complexity and bandwidth consumption.

[0105] In the O-RAN control plane, segment type 5 mainly contains user equipment scheduling information. Its included field, ueId (User Equipment Identifier), is a 15-bit unsigned integer field. In a DMRS-BF environment, ueId is divided into two parts to represent the UE identifier and the UE's layer number. The LSB (least-significant bits) is used to enumerate the layer number of each UE, while the remaining MSB (most-significant bits) is used to enumerate the UE itself; this is simply referred to as the user index. The O-RU uses this division to determine which layers belong to which UEs. This information is crucial because some DMRS-BF signal processing algorithms may utilize the fact that some UE layers belong to the same physical UE, and some RRM (Radio Resource Management) measurements are performed on a per-UE basis, thus representing a combination of UE layer measurement results. The O-RU and O-DU establish communication through ueId, allowing the O-DU to know which configuration corresponds to the results reported by the O-RU.

[0106] In addition to the beamforming methods described above, SRS-based beamforming (SRS-based beamforming) can also be used in O-RAN. In the fronthaul split-processing option, SRS channel estimation and / or further SRS processing functions are located in the O-RU. Based on control plane scheduling messages from the O-DU, the O-RU receives the SRS data from the air interface and then performs channel estimation in the O-RU, without needing to transmit the SRS data to the O-DU. This further effectively reduces the bandwidth of the fronthaul interface and saves beamforming latency. In an SRS environment, the ueId should contain the antenna index information corresponding to the user equipment (UE). When the O-RU supports both SRS-BF and DMRS-BF, the O-RU can refer to the SRS channel estimation results when performing DMRS-BF, thereby improving the performance of DMRS-BF. Multiple antenna indices of the user equipment (UE) in SRS-BF can be simultaneously mapped to the same layer of the user equipment (UE) in DMRS-BF.

[0107] Another advantage of placing SRS-BF processing within the O-RU is that SRS-BF can be used for dimensionality reduction of DMRS-BF. Currently, when the O-RU processes uplink data received from the PUSCH, all data received from all antennas is processed by the DMRS-BF. Current 5G base stations can have up to 64 or more antennas, and the DMRS-BF needs to process data received from all of them. The complexity and resource consumption of this processing are significant. By placing SRS-BF within the O-RU, it can monitor the channel condition of each antenna. If the channel condition falls below a certain threshold, the antenna's quality can be considered problematic. In subsequent calculations, this antenna can be excluded from the computation, thereby reducing the number of data streams that need to be processed and lowering computational complexity. This is the dimensionality reduction benefit of DMRS-BF.

[0108] In O-RAN, both DMRS-BF and SRS-BF use ueId mapping. However, because the validity period of ueId differs between DMRS-BF and SRS-BF, different user indexes can lead to problems where the SRS-BF configuration cannot be found. There are also instances where the same ueId corresponds to different users, resulting in degraded beamforming performance or transmission failures.

[0109] For DMRS-BF, the mapping from ueId to UE layer and eAxC Id should remain consistent within a time slot. However, a UE's ueId may differ in different scheduling time slots. In SRS-BF, a UE's ueId persists for a longer period, meaning that the ueId corresponding to SRS-BF remains unchanged over N consecutive time slots.

[0110] For example, when an O-RU supports both DMRS-BF and SRS-BF, a UE is scheduled in several consecutive time slots. In all time slots, the SRS ueId should be the same. However, if the management plane function UEID-PERSISTENCE (which forces the DU to maintain the same ueId) is not enabled, the DMRS-BF ueId may change. Even if this function is enabled, the ueId will change because the UE is scheduled at different layers in different time slots. The following example will illustrate this:

[0111] Assuming there are 4 time slots, the least significant 3 bits of ueId represent the layer index of DMRS-BF or the port index of SRS-BF, and the remaining 12 most significant bits are used to represent the user index. Here, we assume that the UE has two ports. The content transmitted in the time slots is described below.

[0112] Time slot 3: O-DU transmits the UE's SRS configuration, with ueId being 000001111101 000 and 000001111101 001, corresponding to the SRS configuration and channel estimation information of the two antenna ports, respectively. This ueId remains valid for the next three time slots.

[0113] Time slot 2: O-DU transmits UE's DMRS configuration. At this time, there is only one level of scheduling, and the assigned ueId is 000001111101000.

[0114] Time slot 1: The O-DU transmits the UE's DMRS configuration. At this time, there are 8 layers of scheduling, and the assigned ueId is 000011111010000, 000011111010 001, ... 000011111010 111. Time slot 1 can be assigned the same user index as time slot 2, or it can be assigned a different user index.

[0115] In time slots 1 and 2, when the O-RU wants to use the SRS, for time slot 2, because the user indices of the SRS and DMRS are the same, the O-RU can find the corresponding SRS configuration based on the same user index. However, for time slot 1, the user indices of the SRS and DMRS are different, so the O-RU can only know the configuration corresponding to the DMRS in time slot 1 and cannot find the matching SRS configuration.

[0116] When DMRS-BF wants to use SRS-BF, the O-RU should know the relationship between DMRS-BF and SRS-BF. That is, the O-RU should be able to identify that the DMRS configuration and SRS configuration are for the same UE. Only then can the O-RU use the SRS result for DMRS when performing DMRS-BF, meaning DMRS-BF can refer to the SRS channel estimation result, thereby improving DMRS-BF performance. However, the current O-RAN does not support this. Under the current O-RAN mechanism, the O-DU configures DMRS and SRS separately through different messages, and may even configure them in different time slots. The O-RU cannot identify whether DMRS and SRS are for the same UE, and may use the SRS of unrelated UEs for DMRS-BF, causing SRS channel estimation errors.

[0117] Therefore, a more flexible, dynamic, and scalable approach is needed to indicate the relationship between SRS and DMRS information. To this end, this disclosure proposes two methods to support this.

[0118] The first method involves defining a new extended structure from which the O-RU can retrieve SRS-BF user index information. This method requires the management plane to report O-RU support for this extended structure to the O-DU, and the management plane to report the number of the most significant bits of the user index supported in the ueId. It's important to note that DMRS-BF and SRS-BF can have different numbers of user index bits. In this new extended structure, the SRS-BF user index information can be indicated by including the ueId within the extended structure. The extended structure can contain one or more ueIds, and specifically, there are several implementation methods:

[0119] (i) This extended structure contains a set of ueIds and may also contain NumAntennaPorts. Due to different antenna ports, the O-DU can assign multiple SRS-BF-related ueIds to a UE. For example, the lowest three bits of the ueId represent the port index, and the remaining 12 most significant bits are used to represent the user index. For each layer of the UE, the extended structure will have a corresponding NumAntennaPorts and a corresponding set of ueIds. The value of each NumAntennaPorts is equal to the total number of useful antenna ports allocated to that layer. The ueId contains two parts: the user index of the UE's SRS configuration and the indices of all useful antenna ports allocated to each layer of the UE. For example, assuming the UE has two ports, the O-DU can assign two ueIds to the same UE, where the user index information is the same, the port indices are different, and they are mapped to the same DMRS layer. Under extended structure (i), this extended structure contains two SRS-BF ueIds.

[0120] (ii) This extended structure includes the user index. As in the example above, the lowest three bits of the ueId represent the port index, and the remaining 12 most significant bits represent the user index. For instance, assuming the UE has two ports, the O-DU can assign two ueIds to the same UE, where the user index information is the same, but the port indices are different. Under extended structure (ii), this extended structure contains the user index information.

[0121] (iii) In this extended structure, there is a ueId. The most significant bit on the left of the ueId is fixed as the user index, but the least significant bit on the right can transmit different information. Under the extended structure (iii), the least significant bit of the ueId is the index of any antenna port.

[0122] (iv) In this extended structure, there is a ueId. The most significant bit on the left of the ueId is fixed as the user index, but the least significant bit on the right can convey different information. Under the extended structure (iv), the least significant bit of the ueId is the index of the largest antenna port.

[0123] (v) This extended structure may also include the number of antenna ports that have been allocated to the UE.

[0124] Among them, extension structures 2) to 5) can be used in combination.

[0125] The second method to resolve the binding issue is controlled by the O-RU. This method achieves mapping by forcing the same user to use the same user indexes for both DMRS-BF and SRS-BF. When the O-RU supports both DMRS-BF and SRS-BF, it obtains the number of bits occupied by the user index in the ueId by indicating the number of most significant bits in the management plane. The remaining least significant bits represent the UE's antenna port index or layer index. Here, the user indexes for DMRS-BF and SRS-BF must have the same number of bits. When the O-DU performs SRS configuration within a time slot, if it's a new UE, it assigns a unique user index; if it's reconfiguring an existing UE, it reuses the existing user index. When the O-DU performs DMRS configuration within a time slot, if the UE already has SRS configuration, it uses the corresponding SRS user index; otherwise, it assigns a new user index to the UE.

[0126] Based on the definition and usage of user indexes, the embodiments of this disclosure can be divided into two categories: one is defining a new extended structure, denoted as category A; the other is forcing the same user to use the same DMRS and SRS user indexes, denoted as category B. Embodiment C mainly addresses the problem of asynchronous reference channel information and the latest channel information. Therefore, this disclosure describes three embodiments as examples for illustration, categorized as follows:

[0127] Example A: Transmitting SRS-BF's ueId by Defining a New Extended Structure

[0128] Example B: Mapping is achieved by forcing the same user to use the same DMRS and SRS user indexes.

[0129] Example C: Solving the problem of asynchronous reference channel information and latest channel information by analyzing different scenarios.

[0130] Not limited to the above three embodiments, any case that uses or combines the innovative points of this disclosure is within the protection scope of this disclosure.

[0131] Example A: Transmitting ueId by defining a new extended structure

[0132] Combined with appendix Figure 4 The definition and transmission process of the extended structure for transmitting SRS-BF ueId are described, such as... Figure 4 As shown, the method includes:

[0133] Step 401: The process of O-RU reporting DMRS-BF and SRS-BF capabilities, the number of most significant bits of the user index in ueId, and support for extended structures of SRS-BF ueId to O-DU.

[0134] This process takes place in the management plane of O-RU and O-DU. Segment extensions related to SRS-BF ueId transmission capabilities are added to the segment extension list in the management plane, enabling support for SRS-BF ueId mapping.

[0135] Optionally, the O-RU reports its supported section extensions to the O-DU via a list of supported section extensions. If the supported section extensions include a section extension related to SRS-BFueId transmission capability, then the O-RU supports that section extension. If the supported section extensions do not include a section extension related to SRS-BFueId transmission capability, then the O-RU does not support that section extension.

[0136] Optionally, the O-RU reports to the O-DU the number of bits of the most significant bit in the user index in the ueId used for SRS-BF.

[0137] If the O-DU supports SRS-BF ueId transmission, when the O-DU receives the segment extension list reported by the O-RU, if the O-RU's segment extension list includes segment extensions related to SRS-BF ueId transmission capabilities, then the O-RU also supports SRS-BF ueId segment extension transmission; otherwise, it does not enable SRS-BF ueId segment extension transmission. If the O-DU does not support SRS-BF ueId segment extensions, for backward compatibility, the O-DU ignores the O-RU's information regarding SRS-BF ueId transmission capabilities.

[0138] Step 402, the triggering process of SRS-BF ueId transmission.

[0139] This process takes place in the O-DU, which determines when SRS-BF ueId transmission is necessary. Specifically, if PUSCH is scheduled, the O-DU needs to send segmentation type 5 and segmentation extension 24 to support DMRS-BF. At the same time, the O-RU wants to use SRS-BF to improve PUSCH performance. In this case, the O-DU should attach the SRS-BF ueId segmentation extension before transmission.

[0140] Step 403: The process of creating and sending SRS-BF ueId segment extensions is performed in the O-DU. The creation and sending process of this control plane message is the same as the creation and sending process of existing related control plane messages. The newly added segment extension structure can be defined as shown in Table 1 below. The number of ueIds in the structure shown in Table 1 is the same as the total number of layers for all scheduled users. The content of the ueId representing the antenna port value part can represent the maximum number of ports allocated to each layer for this user.

[0141] Table 1

[0142]

[0143] The descriptions of each extended field in the extended structure shown in Table 1 above are as follows:

[0144] ef (extension flag): occupies 1 bit, extension identifier. When ef = 1, it indicates that there are other segment extensions following this segment extension; when ef = 0, it indicates that this is the last segment extension. It should be understood that if this segment extension exists, the ef flag in its preceding segment description or segment extension should be set to 1.

[0145] extType (extension type): Occupies 7 bits and indicates the extension type. This extension type can be filled with the segment extension number. For example, the numbering starts from 0. If there are other segment extensions before this one (such as extension type 0, extension type 1, and extension type 2), then the extension type number for this segment extension is 3.

[0146] extLen (extension length): occupies 8 bits. It indicates the size of the extension structure and how many 32-bit or 4-byte segments the entire extension occupies.

[0147] ueId: Occupies 15 bits, User Equipment Identifier. In an SRS-BF environment, ueId can be divided into two parts: the user index and the antenna port number. The antenna port number's portion is selected starting from the least significant bit, and its size is determined by the number of antenna ports. The number of antenna ports is controlled by the management plane parameter ueid-max-port-bits reported by the O-RU. An example of ueId parameter partitioning is shown in Table 2.

[0148] Table 2

[0149]

[0150] In this segmented extension, the total number of ueIds can be equal to the total number of UEs scheduled within the message, or it can be equal to the sum of the number of antenna ports for each UE (in this case, it is assumed that the O-DU allocates indices randomly). When the number of ueIds equals the total number of UEs scheduled within the message, each UE has only one ueId. The most significant bit of the ueId is fixed to represent the user index, but the least significant bit can convey different information: 1) the index of any antenna port; 2) the index of the largest antenna port assigned to the UE; 3) the number of antenna indices already assigned to the UE.

[0151] Table 3 shows another implementation method. In the structure shown in Table 3, the total number of ueIds included in this segmented extension is equal to the sum of the number of antenna ports of all UEs scheduled in the message.

[0152] Table 3

[0153]

[0154] The descriptions of each extended field in the extended structure shown in Table 3 above are as follows:

[0155] NumAntennaPorts (number of antenna ports): Occupies 4 bits and indicates the number of antenna ports of the SRS-BF corresponding to each layer of the DMRS-BF user. In this segmented extension, the number of NumAntennaPorts parameters is equal to the number of layers of all scheduled users. The NumAntennaPorts of the first layer indicates the number of SRS-BF ports corresponding to the first layer of the scheduled user, and the number of ueIds following it is the same as the value of the first NumAntennaPorts. The second NumAntennaPorts indicates the number of SRS-BF ports corresponding to the next layer or the first layer of the next user, and the number of ueIds following it is the same as the value of the NumAntennaPorts, and so on, until all layers of all users are listed. This structure contains all ueIds related to SRS configuration.

[0156] For explanations of other fields in Table 3, refer to the explanations of the same fields in Table 1.

[0157] The above description is only one implementation method. According to the first method of the present invention, there are other implementation methods. For the five extended structures mentioned in the first method, only corresponding adaptive modifications are needed. The core idea is to pass the user index information and / or port index of each UE's SRS-BF so that it can be used later. The above method reuses the ueId defined in the existing standard, but in fact, new parameters such as srsPortId can also be defined. The field of the parameter is not necessarily limited to 15 bits.

[0158] Zero padding to ensure 4-byte boundary: Padding with zero bits ensures that the number of bytes occupied by the segmented extension is consistent with the number of bytes defined by extLen.

[0159] Step 404: The process of receiving and parsing the corresponding control plane messages for SRS-BF ueId transmission is performed in the O-RU.

[0160] The O-RU parses the received messages. For control plane messages, it identifies whether they contain segment extensions transmitted via SRS-BS ueId based on the extType field. When the O-RU receives segment type 5, segment extension 24, and SRS-BS ueId transmission extensions, the O-RU should use the user index bits in segment type 5 or segment extension 10 to understand the DMRS information of the UE scheduling layer, and use the user index in the SRS-BS ueId transmission segment extension to understand the port index information of the corresponding UE's SRS, and use it to help improve DMRS-BF, such as using SRS for dimensionality reduction.

[0161] Example B: Mapping is achieved by forcing the same user to use the same DMRS and SRS user indexes.

[0162] Combined with appendix Figure 5 The method for sharing user indexes between DMRS-BF and SRS-BF is described in detail. Figure 5 As shown, the method includes:

[0163] Step 501: The process of O-RU reporting capabilities to O-DU involves the O-RU reporting whether it supports DMRS-BF and SRS-BF via management plane messages, and reporting the highest number of valid bits in the user index (ueId). See step 401 for a detailed implementation.

[0164] Step 502: DMRS and SRS configuration and control plane message sending process

[0165] This process takes place in the O-DU. The O-DU first determines whether the O-RU uses SRS in DMRS-BF, which can be determined in the following three ways:

[0166] 1) The O-RU reports whether the SRS capability is enabled via the management plane. If it is enabled and the O-DU is configured, the O-RU will use the SRS capability when it detects SRS information during DMRS-BF; otherwise, it will not use SRS for enhancement. This method is suitable for situations where the configuration will not change for a long time.

[0167] 2) When the management plane configures the O-DU to enable / activate the function of enhancing DMRS-BF using SRS capabilities, the management plane or the O-DU notifies the O-RU to enable / activate the function of enhancing DMRS-BF using SRS capabilities via management plane messages. When the management plane configures the O-DU to disable / deactivate the function of enhancing DMRS-BF using SRS capabilities, the management plane or the O-DU notifies the O-RU to disable / deactivate the function of enhancing DMRS-BF using SRS capabilities via management plane messages.

[0168] 3) Change the reserved field in the Segmented Extension 24 PUSCH DMRS configuration to srsEnInd. A value of 1 indicates that SRS should be used, while 0 indicates that it should not be used. This method is suitable for finer-grained configuration, allowing changes to the configuration in different time slots. The structure of the modified Segmented Extension 24 can be shown in Table 4:

[0169] Table 4

[0170]

[0171] Some fields in the extended structure shown in Table 4 above are the same as those in the extended structure shown in Table 1 of Example A above. For the sake of brevity, the same fields will not be repeated here. Only the fields newly added in the standard will be described below:

[0172] srsEnInd (SRS Enabled Indication): Occupies 1 bit and indicates whether the DMRS-BF should be used in conjunction with the SRS-BF for enhanced functionality. When srsEnInd = 1, it means that the DMRS-BF should be used in conjunction with the SRS-BF for enhanced functionality; when srsEnInd = 0, it means that the DMRS-BF does not need to be used in conjunction with the SRS-BF.

[0173] Step 503: User Index Configuration Process

[0174] When the O-RU supports both DMRS-BF and SRS-BF, the O-RU uses the management plane to indicate the number of most significant bits of the ueId used to represent the user index, while the remaining least significant bits represent the UE's antenna port index. When the O-RU receives segmentation type 5 and segmentation extension 24, the O-RU should check the value of srsEnInd. If srsEnInd equals 1, it indicates that SRS-BF will be used for DMRS-BF, and both SRS-BF and DMRS-BF will use the same UE index.

[0175] When the O-DU performs SRS-BF configuration within a time slot, if it is a new UE, a unique user index is assigned to it; if it is a reconfiguration of an existing UE, the existing user index is reused.

[0176] When the O-DU performs DMRS-BF configuration in a time slot, if the function of enhancing DMRS-BF using SRS capabilities is enabled or activated, and the UE already has SRS-BF configuration (i.e., an assigned SRS-BF-related ueId), the O-DU configures the user index in the DMRS-BF-related ueId to be identical to the SRS-BF user index. Using the same user index, the O-RU can use the SRS-BF results for DMRS-BF. When performing DMRS-BF, the O-RU can refer to the SRS-BF channel estimation results, thereby improving DMRS-BF performance. If SRS-BF has not yet been configured, the O-DU assigns a new user index to the UE, which can be used for the SRS-BF ueId and / or the DMRS-BF ueId.

[0177] Figure 6 A flowchart illustrating a method performed by a first network node according to various embodiments of the present disclosure is shown.

[0178] refer to Figure 6 In step S601, the first network node determines whether the probe reference signal beamforming SRS-BF is used to perform demodulation reference signal beamforming DMRS-BF.

[0179] In step S602, if SRS-BF is used to execute DMRS-BF, the first network node sends first information including a first user equipment identifier of DMRS-BF and second information including a second user equipment identifier of SRS-BF to the second network node, wherein the first user equipment identifier and the second user equipment identifier indicate the same user equipment UE.

[0180] Figure 7 A flowchart illustrating a method performed by a second network node according to various embodiments of the present disclosure is shown.

[0181] refer to Figure 7 In step S701, the second network node receives from the first network node first information including a first user equipment identifier of a demodulated reference signal beamforming (DMRS-BF) and second information including a second user equipment identifier of a probed reference signal beamforming (SRS-BF), wherein the first user equipment identifier and the second user equipment identifier indicate the same user equipment (UE).

[0182] In step S702, the second network node executes DMRS-BF based on SRS-BF according to the first user equipment identifier and the second user equipment identifier.

[0183] Figure 8 A flowchart illustrating a method performed by a first network node according to various embodiments of the present disclosure is shown.

[0184] refer to Figure 8 In step S801, the first network node determines whether the probe reference signal beamforming SRS-BF is used to perform demodulation reference signal beamforming DMRS-BF.

[0185] In step S802, if SRS-BF is used to execute DMRS-BF, the first network node sends first information including the first user equipment identifier of DMRS-BF and first indication information to the second network node, wherein the first indication information is used to instruct the second network node to use the same user index as the user index of the first user equipment identifier for SRS-BF.

[0186] Figure 9 A flowchart illustrating a method performed by a second network node according to various embodiments of the present disclosure is shown.

[0187] refer to Figure 9 In step S901, the second network node receives from the first network node first information including a first user equipment identifier of the demodulated reference signal beamforming DMRS-BF and first indication information, wherein the first indication information is used to instruct the second network node to use the same user index as the user index of the first user equipment identifier for probed reference signal beamforming SRS-BF.

[0188] In step S902, the second network node performs DMRS-BF based on the user index of DMRS-BF and the user index of SRS-BF.

[0189] Example C: Solving the problem of asynchronous reference channel information and latest channel information by analyzing different scenarios.

[0190] Figure 10An implementation example for resolving the channel information asynchrony problem is described. When the SRS-BF result is used for DMRS-BF, a channel information asynchrony problem still exists between the O-DU and O-RU. Specifically, the O-DU schedules PUSCH resources based on the Channel Information (CI) received from the O-RU (referred to as the reference CI). When channel estimation is performed in the O-DU, the O-DU schedules PUSCH based on the reference channel information and sends the channel information, PUSCH configuration, and DMRS configuration to the O-RU. The O-RU uses these configurations and channel information to process PUSCH data. Thus, the channel information between the O-DU and O-RU is synchronized. When SRS-BF is in the O-RU, the O-RU performs channel estimation calculations and then reports the channel information (CI) to the O-DU. The O-DU schedules PUSCH resources based on the received CI. The O-DU sends DMRS-BF and PUSCH configuration messages to the O-RU. When the O-RU receives PUSCH data from the UE, it obtains the latest channel information (CI) through SRS-BF and then uses the latest CI to reduce the dimensionality of DMRS-BF. However, a problem arises: if the difference between the reference CI and the latest CI is large, it's best not to use the latest CI to generate DMRS-BF weights; that is, the results of SRS-BF should not be applied to DMRS-BF. Otherwise, DMRS-BF performance will be degraded. This is the synchronization problem between the O-DU and O-RU. This situation occurs if the channel state changes rapidly and the SRS period is short. If the difference between the reference CI and the latest CI is large, the synchronization problem between the O-RU and O-DU may degrade system performance. How to resolve the synchronization between the reference CI in the O-DU and the latest CI in the O-RU is another issue. Figure 10 An embodiment for resolving the channel information asynchrony problem is described. This embodiment reduces issues such as decreased channel quality, system capacity, and user experience caused by inconsistency when the reference CI used by the O-DU for PUSCH scheduling differs from the latest CI used by the O-RU for latest data processing.

[0191] The following is a more detailed explanation. For PUSCH and DMRS configuration, the O-DU needs to perform the following three steps, spanning multiple time slots. In TS0, the O-DU determines the PUSCH scheduling configuration based on available channel information. In TS1, the O-DU prepares the CP message, such as ST5+SE24. In TS2, the O-DU sends the CP message to the O-RU. However, when the O-RU supports SRS-BF, it calculates the latest CI. The O-RU should process the PUSCH based on the latest channel information. When the O-DU configures PUSCH and DMRS-BF, it does so based on the old CI, for example, the UE antenna ports should be 1 and 2. Based on the latest channel information, the optimal UE antenna ports are 3 and 4. Using the latest channel information for dimensionality reduction may increase decoding errors.

[0192] Step 1001: The O-RU reports to the O-DU whether the O-RU supports SRS-BF. This function can be reported using new parameters defined in the management plane.

[0193] Step 1002: The O-DU sends SRS-related configuration information to the O-RU.

[0194] The O-DU transmits the SRS configuration to the O-RU in each SRS scheduling cycle (e.g., 8 time slots) via segmentation type yy (ST yy). ST yy is a new segmentation type for transmitting SRS configuration to the O-RU. The O-RU can calculate the channel quality based on the received SRS configuration. This calculation is performed in each SRS scheduling cycle. The quality of each antenna can be obtained through SRS-BF calculation. This result can be used for DMRS-BF dimensionality reduction. The O-RU can report channel information to the O-DU. The O-DU sends the DMRS configuration to the O-RU via ST 5 and SE 24, which can be transmitted by time slot. The O-RU processes PUSCH data via DMRS-BF and takes into account the results of SRS-BF, for example, processing only data received from antenna ports with good quality and discarding data received from other antenna ports.

[0195] In this message, the O-DU can also provide SRS-related information, such as the SRS period and user priority, to the O-RU. This helps the O-RU report channel information in advance to prevent synchronization problems.

[0196] Step 1003: The O-DU determines the PUSCH scheduling and DMRS configuration for each time slot. The O-DU also determines whether SRS-BF can be used to reduce the dimensionality of the DMRS.

[0197] The information from O-DU can be divided into the following four cases, and the behavior of O-DU is different in each case.

[0198] Scenario 1: Based on the received CI, the O-DU can determine that the channel information CI in the O-RU and O-DU is basically consistent. No special processing is required in the O-DU. The O-DU determines whether the SRS can be used to enhance DMRS-BF. If so, it sends a new segment extension containing binding information appended to the DMRS configuration.

[0199] Scenario 2: Scheduling information is transmitted using reference channel information CI-1 in time slot N-2. New channel information CI-2 is obtained in time slot N. Since the new reference channel information CI-2 is obtained during the control plane message transmission phase, if CI-2 differs significantly from CI-1, but scheduling is based on time slot N, rescheduling would not allow enough time to send the PUSCH scheduling and DMRS configuration for time slot N to the O-RU. Therefore, the O-DU cannot perform rescheduling. The O-DU decides whether SRS (based on the old channel information CI) should be used for DMRS. This decision can be based on the SRS period, sub-band, or full-band. For example, using a shorter SRS period means the channel environment changes rapidly, so the determined DMRS-BF channel information may be unreasonable. In this case, the O-DU may decide not to use the SRS channel information CI to enhance DMRS-BF to avoid performance degradation, i.e., not to connect new segment extensions.

[0200] Scenario 3: Scheduling information is transmitted using reference channel information CI-1 in time slot N-2. A new CI-2 is obtained in time slot N-1. Since the new reference CI-2 is obtained during the control plane message preparation phase, partial rescheduling is possible. For some users, the latest CI-2 is received earlier, allowing the O-DU to generate control plane scheduling information in a timely manner. For some users, the latest CI-2 is received later, and the O-DU does not have time to generate new control plane scheduling information based on the new channel information CI-2.

[0201] Scenario 4: Scheduling information is transmitted using reference channel information CI-1 in time slot N-2. New channel information CI-2 is obtained in time slot N-2. Since the new reference channel information CI-2 was obtained during the control plane scheduling information generation phase, rescheduling can be performed.

[0202] Step 1004: The O-DU sends a control plane configuration message to the O-RU.

[0203] If PUSCH is scheduled, the O-DU sends a control plane configuration message (ST5 + SE24) for DMRS-BF configuration. ST5 contains UE scheduling information, including PRB resources and ueId. SE24 works in conjunction with ST5 to deliver the PUSCH DMRS configuration for each UE (indicated by the ueId in ST5). The O-RU processes the PUSCH data received from the UE according to the DMRS configuration in that time slot and reports the RRM measurement results to the O-DU via segment type 10. Segment type 10 contains the UE's ueId and the RRM measurement report.

[0204] In addition, the control plane configuration message can also carry SRS-BF indication information for DMRS-BF, which can be obtained through one of the following two methods:

[0205] a) O-DU Control Method: A new segment extension is created to indicate whether DMRS-BF enhancement is enabled. The segment extension contains the assigned user index and antenna port list, which will be used for DMRS-BF enhancement; this new segment extension has been described in the above embodiments and is omitted here.

[0206] b) O-RU Control Method: The O-DU forces SRS-BF and DMRS-BF to use the same user index and uses a flag to instruct the O-RU to use SRS-BF for DMRS-BF. The selected port for DMRS-BF is determined by the O-RU. If PUSCH has already been scheduled and SRS-BF cannot be used for DMRS enhancement, the O-DU should send an ST5 + SE24 message without the flag information. This flag information has been described in the above embodiments and is omitted here.

[0207] Step 1005: The O-RU receives the control plane configuration message, parses the binding information to obtain the UE's SRS information, and uses it to perform DMRS-BF dimensionality reduction. The O-RU determines the priority of channel information reporting based on the UE priority and SRS period, and judges whether there may be a synchronization problem between the reference CI and the latest CI. If so, the O-RU will report the latest CI of the UE in advance according to the UE's priority.

[0208] The O-RU determines the priority of Channel Information (CI) reports based on user priority and SRS period. As an enhancement, if the O-RU receives information related to SRS period and user priority, it can report the highest-level user channel information to the O-DU as early as possible, which will benefit the O-DU's scheduling. If the O-RU knows the SRS period and user priority, it can determine whether to check the effectiveness of DMRS enhancement and decide whether to adopt DMRS enhancement based on whether the performance of the enhanced DMRS is better than that of the unenhanced DMRS.

[0209] Step 1006: The O-RU sends an SRS channel estimation report to the O-DU.

[0210] The SRS channel estimation report contains the latest channel estimation results.

[0211] Figure 11 A block diagram of a network node 1100 according to various embodiments of the present disclosure is shown. The network node 1100 may include an O-DU or an O-RU.

[0212] refer to Figure 11 The network node 1100 according to various embodiments of the present disclosure may include a transceiver 1101 and a controller 1102. For example, the transceiver 1101 may be configured to transmit and receive signals. For example, the controller 1102 may be coupled to the transceiver 1101 and configured to perform the aforementioned methods.

[0213] Those skilled in the art will understand that the illustrative embodiments described above are not intended to be limiting. It should be understood that any two or more of the embodiments disclosed herein can be combined in any combination. Furthermore, other embodiments may be utilized and other changes may be made without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that aspects of the invention disclosed herein, as generally described herein and illustrated in the accompanying drawings, can be arranged, substituted, combined, separated, and designed in a variety of different configurations, all of which are contemplated herein.

[0214] Those skilled in the art will understand that the various illustrative logic blocks, modules, circuits, and steps described herein can be implemented in hardware, software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in the form of sets of functions. Whether such sets of functions are implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described sets of functions in different ways for each specific application, but such design decisions should not be construed as departing from the scope of this application.

[0215] The various illustrative logic blocks, modules, and circuits described in this application may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0216] The steps of the methods or algorithms described in this application may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0217] In one or more exemplary designs, the functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, the latter including any medium that facilitates the transfer of a computer program from one location to another. Storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0218] The above description is merely an exemplary embodiment of this application and is not intended to limit the scope of protection of this application. The scope of protection of this application is determined by the appended claims.

Claims

1. A method performed by a first network node in a wireless communication system, comprising: Receive first information related to the second network node supporting probe reference signal beamforming (SRS-BF); A configuration message for demodulation reference signal beamforming (DMRS-BF) is sent to the second network node. The configuration message includes configuration information related to the first UE corresponding to the DMRS-BF and configuration information related to the second UE corresponding to the SRS-BF.

2. The method of claim 1, wherein, Send a DMRS-BF configuration message to the second network node, including: When SRS-BF can be applied to DMRS-BF, a DMRS-BF configuration message is sent to the second network node. The configuration message includes configuration information related to the first UE and configuration information related to the second UE.

3. The method according to claim 1, wherein, The first UE-related configuration information is carried in the first segment extension of the configuration message; The second UE-related configuration information is carried in the second segment extension corresponding to the first segment extension in the configuration message.

4. The method according to claim 3, wherein, The first segmented extension includes at least one first extended field, and the second segmented extension includes at least one second extended field. The first extended field that includes the first UE-related configuration information corresponds to the second extended field that includes the second UE-related configuration information.

5. The method according to claim 3, wherein, The first information includes: The identification information of the second segment extension.

6. The method according to claim 3, wherein, The second segmentation expansion includes at least one of the following: UE index related information; Antenna port related information.

7. The method according to claim 6, wherein, The antenna port related information includes at least one of the following: At least one antenna port index; Number of antenna ports; The index of the antenna port with the largest index value.

8. The method according to claim 1, wherein, The DMRS-BF and the SRS-BF correspond to the same UE; The second UE-related configuration information includes: indication information indicating that the DMRS-BF and the SRS-BF correspond to the same UE.

9. The method according to claim 1, wherein, Receive first information related to the second network node's support for SRS-BF from the second network node, including: Receive management plane messages from the second network node, the management plane messages including first information related to the second network node supporting SRS-BF.

10. The method according to claim 1, wherein, Send a DMRS-BF configuration message to the second network node, including: Send control plane messages to the second network node, the control plane messages including DMRS-BF configuration messages.

11. The method according to claim 1, wherein, Send a DMRS-BF configuration message to the second network node, including: When the scheduling and processing of the Physical Uplink Shared Channel (PUSCH) fall within the same SRS channel information reporting period, a DMRS-BF configuration message is sent to the second network node.

12. The method according to claim 1, further comprising: Send SRS configuration information to the second network node, wherein the SRS configuration information includes at least one of the following: SRS configuration period and UE priority information; Channel information is received from the second network node, which is determined by the second network node based on the SRS configuration information.

13. A method performed by a second network node in a wireless communication system, comprising: Send first information to the first network node related to the second network node's support for probe reference signal beamforming (SRS-BF); The configuration message for demodulation reference signal beamforming (DMRS-BF) is received from the first network node. The configuration message includes configuration information related to the first UE corresponding to the DMRS-BF and configuration information related to the second UE corresponding to the SRS-BF.

14. The method according to claim 13, wherein, Receive DMRS-BF configuration messages from the first network node, including: When SRS-BF can be applied to DMRS-BF, a configuration message for DMRS-BF is received from the first network node. The configuration message includes configuration information related to the first UE and configuration information related to the second UE.

15. The method according to claim 13, wherein, The first UE-related configuration information is carried in the first segment extension of the configuration message; The second UE-related configuration information is carried in the second segment extension corresponding to the first segment extension in the configuration message.

16. The method according to claim 15, wherein, The first segmented extension includes at least one first extended field, and the second segmented extension includes at least one second extended field. The first extended field that includes the first UE-related configuration information corresponds to the second extended field that includes the second UE-related configuration information.

17. The method according to claim 15, wherein, The first information includes: The identification information of the second segment extension.

18. The method according to claim 15, wherein, The second segmentation expansion includes at least one of the following: UE index related information; Antenna port related information.

19. The method according to claim 18, wherein, The antenna port related information includes at least one of the following: At least one antenna port index; Number of antenna ports; The index of the antenna port with the largest index value.

20. The method according to claim 13, wherein, The DMRS-BF and the SRS-BF correspond to the same UE; The second UE-related configuration information includes: indication information indicating that the DMRS-BF and the SRS-BF correspond to the same UE.

21. The method according to claim 13, wherein, Send first information related to the second network node's support for SRS-BF to the first network node, including: A management plane message is sent to the first network node, the management plane message including first information related to the second network node supporting SRS-BF.

22. The method according to claim 13, wherein, Receive DMRS-BF configuration messages from the first network node, including: Receive control plane messages from the first network node, the control plane messages including DMRS-BF configuration messages.

23. The method according to claim 13, wherein, Receive DMRS-BF configuration messages from the first network node, including: When the scheduling and processing of the Physical Uplink Shared Channel (PUSCH) fall within the same SRS channel information reporting period, the configuration message of DMRS-BF is received from the first network node.

24. The method of claim 13, further comprising: Receive SRS configuration information from the first network node, wherein the SRS configuration information includes at least one of the following: SRS configuration period and UE priority information; Channel information is determined based on the SRS configuration information; The channel information is sent to the first network node.

25. The method of claim 13, further comprising: The DMRS-BF is executed based on the configuration message of the DMRS-BF.

26. A network node in a wireless communication system, comprising: transceiver; as well as A controller, coupled to the transceiver and configured to perform the method according to any one of claims 1-25.

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