Channel Status Information (CSI) Feedback Reporting in Wireless Networks

Abstract

Embodiments of the present disclosure disclose a base station (BS) distributed unit (DU) 102. The BS-DU 102 is configured to transmit a channel status information reference signal CSI-RS and a physical resource block PRB group size to a user device (UE) 104, so that the UE 104 uses the PRB group size to perform CSI prediction of a radio channel between the UE 104 and the BS-DU 102, to periodically receive ground truth CSI-RS from the UE 104, to determine the values ​​of one or more channel selectivity parameters of the radio channel based on the ground truth CSI-RS received from the UE 104, to determine an updated PRB group size based on the values ​​of one or more channel selectivity parameters, and to transmit the updated PRB group size to the UE 104, so that the UE 104 uses the updated PRB group size to perform CSI prediction of a radio channel.

Description

[Technical Field]

[0001] [Cross-reference to related applications] This application claims priority to Indian Provisional Application No. 202341052059, filed on 2 August 2023, entitled “Method and System for Transmitting Channel State Information (CSI) Feedback with Different Granularity,” and Indian Application No. 202341052059, filed on 15 December 2023, entitled “Channel State Information (CSI) Feedback Reporting in Wireless Networks,” both of which are expressly incorporated herein by reference.

[0002] [Technical field] This disclosure relates to channel status information (CSI) feedback reporting in wireless networks. [Background technology]

[0003] In wireless communication networks, for example in 5G NR (5th Generation New Radio), channel status information (CSI) describes the channel characteristics of a radio channel or communication link. For example, CSI describes signal propagation characteristics such as scattering, fading, and power attenuation. The channel status information reference signal (CSI-RS) is a reference signal (RS) used in the downlink (DL) direction. Here, CSI-RS is used for channel sounding purposes and is used to measure the characteristics of the radio channel so that the channel can utilize the correct modulation, code rate, beamforming, etc. Generally, base stations associated with wireless communication networks (e.g., gNodeB or gNB) transmit CSI-RS in the DL in a periodic or irregular manner. User equipment (UE) performs CSI prediction in response to the CSI-RS received from the base station. In one example, the UE may measure CSI such as transmit rank, precoder matrix indicator, and channel quality indicator.

[0004] The UE performs CSI prediction based on CSI-RS samples actually received from the base station in DL. Notably, CSI prediction is not performed for each individual physical resource block (PRB), but rather for groups of PRBs (e.g., 2 PRBs, 4 PRBs, 8 PRBs, etc.). Here, the size of the PRB group depends directly on the channel's frequency selectivity. The size of the PRB group to be used for CSI prediction is provided to the UE via radio resource control (RRC) signaling.

[0005] Furthermore, with advancements in communication technology, there are advanced technologies that use artificial intelligence (AI) / machine learning (ML)-based CSI estimation and prediction. In such technologies, each of the multiple UEs in a wireless communication network transmits CSI feedback, along with supporting information, to the base station in order to improve CSI feedback.

[0006] The information disclosed in this background section of the disclosure is intended solely to improve the understanding of the general background art of the present invention and should not be construed as a confirmation or suggestion in any way that such information constitutes prior art already known to those skilled in the art. [Overview of the project] [Means for solving the problem]

[0007] In one embodiment, the present disclosure discloses a Base Station (BS) Distributed Unit (DU). The BS-DU is configured to transmit a Channel State Information Reference Signal (CSI-RS) and a Physical Resource Block (PRB) group size to a User Equipment (UE). The UE uses the PRB group size to perform CSI prediction for a radio channel between the UE and the BS-DU. Furthermore, the BS-DU periodically receives a ground-truth CSI-RS from the UE. The BS-DU determines values of one or more channel selectivity parameters of the radio channel based on the ground-truth CSI-RS received from the UE. Furthermore, the BS-DU determines an updated PRB group size based on a change in the values of the one or more channel selectivity parameters. Thereafter, the BS-DU transmits the updated PRB group size to the UE. The UE uses the updated PRB group size to perform CSI prediction for the radio channel.

[0008] In one embodiment, the present disclosure discloses a method. The method comprises transmitting a Channel State Information Reference Signal (CSI-RS) and a Physical Resource Block (PRB) group size to a User Equipment (UE). The UE uses the PRB group size to perform CSI prediction for a radio channel between the UE and the BS-DU. Furthermore, the method comprises periodically receiving a ground-truth CSI-RS from the UE. The method comprises determining values of one or more channel selectivity parameters of the radio channel based on the ground-truth CSI-RS received from the UE. Furthermore, the method comprises determining an updated PRB group size based on a change in the values of the one or more channel selectivity parameters. Thereafter, the method comprises transmitting the updated PRB group size to the UE. The UE uses the updated PRB group size to perform CSI prediction for the radio channel.

[0009] In one embodiment, the present disclosure discloses a non-transitory computer-readable medium. The non-transitory computer-readable medium comprises instructions for performing an operation comprising transmitting channel state information reference signal (CSI-RS) and physical resource block (PRB) group size to user equipment (UE). The UE performs CSI prediction for a radio channel between the UE and a BS-DU, taking into account the configured PRB group size. Further, the operation comprises periodically receiving ground truth CSI-RS from the UE. The operation comprises determining values of one or more channel selectivity parameters of the radio channel based on the ground truth CSI-RS received from the UE. Further, the operation comprises determining an updated optimal PRB group size based on changed values of the one or more channel selectivity parameters. The operation then comprises transmitting the updated PRB group size to the UE. The UE performs CSI prediction for the radio channel using the updated PRB group size.

[0010] The above summary is for illustrative purposes only, and is not intended to be limiting in any manner. In addition to the exemplary aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The novel features and characteristics of the present disclosure are set forth in the appended claims. However, the present disclosure itself, preferred modes of use, further objects, and advantages thereof will be best understood by reference to the following detailed description of exemplary embodiments when read in conjunction with the accompanying drawings. In the following, one or more embodiments are described by way of example only, with reference to the accompanying drawings, wherein like reference numerals represent like elements.

[0012] Figure 1 illustrates an exemplary environment for reporting channel status information (CSI) in a wireless network, according to some embodiments of the present disclosure.

[0013] Figure 2 illustrates a detailed diagram of a base station (BS) distributed unit (DU) in a wireless network according to some embodiments of the present disclosure.

[0014] Figure 3 shows an exemplary flowchart for reporting CSI in a wireless network according to some embodiments of the present disclosure.

[0015] Figure 4 shows an exemplary flowchart illustrating method steps for reporting CSI in a wireless network according to some embodiments of the present disclosure.

[0016] Figure 5 shows a block diagram of a general-purpose computing system for reporting CSI in a wireless network, according to an embodiment of the present disclosure.

[0017] Those skilled in the art should understand that each block diagram presented herein represents a conceptual diagram of an exemplary system embodying the principles of this subject. Similarly, flowcharts, flow charts, state transition diagrams, pseudocode, etc., are understood to represent various processes that may be executed by a computer or processor, whether or not the computer or processor is explicitly indicated, and which are substantially represented in a computer-readable medium. [Modes for carrying out the invention]

[0018] In this document, the term “exemplary” is used herein to mean “serving as an example, illustration, or representation.” No embodiment or implementation of this subject matter described herein as “exemplary” is necessarily construed as preferable or advantageous to any other embodiment.

[0019] While various modifications and alternative forms are possible for this disclosure, specific embodiments are illustrated in the drawings and described in detail below. However, this disclosure is not intended to limit itself to any particular form, but rather should be understood as covering all modifications, equivalents, and substitutions within the scope of this disclosure.

[0020] The terms “equipped,” “possessing,” or any other variation thereof, are intended to cover non-exclusive inclusion, meaning that a setup, device, or method comprising a list of components or steps may include other components or steps that are not explicitly listed or are inherent to such setup, device, or method, rather than including only those components or steps. In other words, the presence of one or more elements in a system or apparatus accompanied by “equipped” does not, unless more restrictive, preclude the presence of other or additional elements in the system or apparatus.

[0021] Channel status information (CSI) describes the channel characteristics of a radio channel or communication link in a wireless communication network. For example, CSI describes signal propagation characteristics such as scattering, fading, and power attenuation. The channel status information reference signal (CSI-RS) is a reference signal (RS) used in the downlink (DL) direction. Here, CSI-RS is used for channel sounding purposes and is used to measure the characteristics of the radio channel so that the channel can utilize the correct modulation, code rate, beamforming, etc. Generally, base stations associated with wireless communication networks (e.g., gNodeB or gNB) transmit CSI-RS in the DL in a periodic or irregular manner. User equipment (UE) performs CSI prediction in response to the CSI-RS received from the base station. In one example, the UE may measure CSI such as transmit rank, precoder matrix indicator, and channel quality indicator.

[0022] The UE performs CSI prediction based on CSI-RS samples actually received from the base station in DL. Notably, CSI prediction is not performed for each individual physical resource block (PRB), but rather for groups of PRBs. The size of the PRBs may vary. For example, CSI prediction may be performed for 2 PRBs, 4 PRBs, 8 PRBs, etc. Here, the size of the PRB group directly depends on the radio channel selectivity. For example, high frequency selectivity suggests a small PRB group size, and low frequency selectivity suggests a large PRB group size.

[0023] The PRB size to be used for CSI prediction is provided to the UE via radio resource control (RRC) signaling. In conventional systems, once the PRB size is initially provided to the UE, there is no procedure for dynamically updating or optimizing the PRB size based on radio channel selectivity. The PRB size affects the performance of CSI prediction at the UE. Therefore, updating or optimizing the PRB size based on radio channel selectivity is required.

[0024] Furthermore, with advancements in communication technology, there are advanced technologies that use artificial intelligence (AI) / machine learning (ML)-based CSI estimation and prediction. In such technologies, each of the multiple UEs in a wireless communication network transmits CSI feedback, along with supporting information, to the base station in order to improve CSI feedback. However, this results in significant uplink overhead because numerous UEs communicate the improved CSI feedback to the base station in the wireless communication network.

[0025] This disclosure provides a base station (BS) distributed unit (DU) and method for overcoming the limitations described above. In this disclosure, the BS-DU initially transmits the CSI-RS and PRB group size, and then periodically receives ground truth CSI-RS from the user equipment (UE). Based on the ground truth CSI-RS, the BS-DU monitors the channel selectivity parameters of the radio channel between the UE and the BS-DU. Based on the channel selectivity parameters of the radio channel, the BS-DU determines whether the PRB group size needs to be updated. Thus, the BS-DU updates the PRB group size and transmits the updated PRB group size to the UE. The UE uses the updated PRB group size to perform CSI forecasting. Thus, this disclosure provides a procedure for dynamically updating or optimizing the PRB group size based on channel selectivity parameters, which ensures increased accuracy in CSI forecasting and reporting at the UE.

[0026] Notably, CSI-RS is predicted at the UE, and CSI feedback information is sent to the gNB along with a PRB of varying granularity. Predicting CSI feedback with varying PRB granularity involves dynamically inferring channel characteristics. By using finer granularity during periods of rapid channel fluctuation or high mobility, and coarser granularity when channel conditions are stable or resources are limited, wireless communication networks optimize resource utilization and efficiently adapt their transmission parameters. This dynamic approach improves spectral efficiency, reduces interference, boosts overall network capacity, and ensures reliable, high-quality communication services for users in wireless environments.

[0027] In this disclosure, the UE generates CSI feedback based on the channel parameters of the radio channel. Therefore, the PRB granularity of the CSI feedback reporting is reduced based on the channel parameters, and compressed CSI feedback can be transmitted to the BS-DU. This ensures that uplink overhead in the wireless communication network is reduced without losing channel information. Furthermore, since the CSI feedback channel has very stringent error requirements, reducing the overhead significantly reduces the uplink resources required for transmission.

[0028] Figure 1 illustrates an exemplary environment 100 for reporting CSI feedback in a wireless network according to an embodiment of the present disclosure. The exemplary environment 100 comprises a base station (BS) distributed unit (DU) 102, user equipment (UE) 104, and a base station (BS) aggregate unit (DU) 106. BS-DU 102 and BS-CU 106 are part of a base station, gNodeB, or gNB. The description in this disclosure is explained with regard only to fifth-generation (5G) networks. However, this disclosure is applicable to any type of network, such as fourth-generation (4G) networks and 5G networks. In a 5G network, the gNB functions as a 5G base station, responsible for the efficient transmission and reception of radio signals to and from the UE. The gNB manages critical functions such as radio resource control (RRC), mobility management, and connectivity control. The 5G core (5GC) provides core network functions that facilitate scalability and support a variety of services and applications. Various functional nodes, such as Access and Mobility Management (AMF), Session Management (SMF), and User Plane (UPF), are part of 5GC.

[0029] In a 5G network, a base station is divided into three distinct components: an aggregation unit (CU) (referred to as BS-CU106 in this description), a distributed unit (DU) (referred to as BS-DU102 in this description), and a remote radio unit (RU). The BS-CU106 acts as a central intelligence, agilely handling complex aggregated network functions. These functions include, but are not limited to, expert radio resource management, effective network control, and seamless coordination with the 5GC. The BS-DU102 is responsible for managing data plane processing, including critical tasks such as transmitting and receiving data with the user equipment (UE) 104. The BS-DU102 interfaces seamlessly with the BS-CU106 on the F1 interface. The RU handles physical layer functions, housing antennas and radio transceivers that facilitate the actual transmission and reception of radio signals.

[0030] UE104 represents an end-user device that accesses services and applications over a wireless network. UE104 is configured to connect to BS-DU102 over the wireless network. Examples of UE104 include, but are not limited to, any device used by a user to communicate over a wireless network, such as mobile phones, smartphones, laptops, wearables, and IoT (Internet of Things).

[0031] This disclosure relates to reporting of CSI feedback in a wireless network. Channel status information (CSI) describes the channel characteristics of a wireless channel or communication link. For example, CSI describes signal propagation characteristics such as scattering, fading, and power attenuation. The channel status information reference signal (CSI-RS) is a reference signal (RS) used in the downlink (DL) direction. Here, the CSI-RS is used for channel sounding purposes and is used to measure the characteristics of the wireless channel so that the channel can utilize the correct modulation, code rate, beamforming, etc. Generally, BS-DU102 transmits CSI-RS in a periodic or irregular manner in the DL. UE104 performs CSI prediction in response to the CSI-RS received from BS-DU102. In one example, UE104 may measure CSI such as transmit rank, precoder matrix indicator, and channel quality indicator. UE104 performs CSI prediction for groups of physical resource blocks (PRBs), such as 2 PRBs, 4 PRBs, etc. PRBs are resource blocks used for actual transmission / reception in a wireless network. In an exemplary implementation, a PRB consists of 12 subcarriers on which transmission / reception is scheduled.

[0032] In this disclosure, BS-DU102 is configured to transmit CSI-RS and PRB group size to UE104. UE104 performs CSI prediction for the radio channel between UE104 and BS-DU102 for the configured PRB group size. For example, the PRB group size may be 4. In this case, UE104 performs CSI prediction for 2 PRBs. BS-DU102 may configure the PRB group size based on channel characteristics when it establishes an initial connection with UE104. In this disclosure, BS-DU102 periodically receives ground truth CSI-RS from UE104. The ground truth CSI-RS is received so that BS-DU102 can periodically monitor channel characteristics and determine whether an update to the PRB group size is necessary based on those characteristics.

[0033] BS-DU102 determines the values ​​of one or more channel selectivity parameters of the radio channel based on the ground truth CSI-RS received from UE104. The one or more channel selectivity parameters may include at least one of frequency selectivity, spatial selectivity, and temporal selectivity of the radio channel. In one example, BS-DU102 may determine the rate of change of the amplitude of the signal transmitted on the radio channel over time. Based on the change in the value of one or more channel selectivity parameters, BS-DU102 determines the updated PRB group size. For example, BS-DU102 may determine a higher rate of change of the signal amplitude over time. BS-DU102 may determine that the PRB size needs to be updated. In such a case, the updated PRB group size may be determined to be 4. BS-DU102 may then transmit the updated PRB group size to UE104. In one embodiment, BS-DU102 may send a request to BS-CU106 indicating the updated PRB group size. BS-CU106 may acknowledge the request and send a Radio Resource Control (RRC) reconfiguration message to UE104 indicating the updated PRB group size. In another embodiment, BS-DU102 may send the updated PRB group size to UE104 in a Layer 2 media access control message. UE104 uses the updated PRB group size to perform CSI prediction for the radio channel. Thus, this disclosure enables dynamic updating of the PRB group size based on channel characteristics. This allows for consideration of an optimized PRB group size and increases the accuracy of CSI prediction performed by UE104.

[0034] In one embodiment, BS-DU102 receives compressed CSI feedback from UE104 in response to CSI-RS transmission. Here, UE104 generates compressed CSI feedback based on ground truth CSI-RS and one or more channel parameters of the radio channel. UE104 optimizes the granularity of CSI feedback reporting based on the channel parameters. This ensures that uplink overhead in the wireless communication network is reduced without losing channel information.

[0035] Figure 2 illustrates a detailed diagram of BS-DU102 in a wireless network according to some embodiments of the present disclosure. BS-DU102 may include an input / output (I / O) interface 202, a memory 204, and a central processing unit (also referred to as "CPU" or "processor 206"). In some embodiments, the memory 204 may be communicatively coupled to the processor 206. The memory 204 stores instructions executable by the processor 206. The processor 206 may include at least one data processor for executing program components to perform user or system generation requests. The memory 204 may be communicatively coupled to the processor 206. The memory 204 stores instructions executable by the processor 206, which, when executed, may cause the processor 206 to send updated PRB group sizes for CSI estimation and CSI feedback reporting. The I / O interface 202 is coupled to the processor 206, and input and / or output signals are communicated. For example, BS-DU102 may transmit the updated PRB group size to UE104 via the I / O interface 202. In one embodiment, BS-DU102 may be implemented in various computing systems such as servers, network servers, and cloud-based servers.

[0036] In one embodiment, the memory 204 may include one or more modules 210 and data 208. One or more modules 210 may be configured to use the data 208 to perform the steps of the disclosure. In one embodiment, each of the one or more modules 210 may be a hardware unit which may be coupled with BS-DU102 outside of the memory 204. As used herein, the term module 210 represents an Application Specific Integrated Circuit (ASIC), an electronic circuit, a field-programmable gate array (FPGA), a programmable system-on-chip (PSoC), a combinational logic circuit, and / or other appropriate component that provides the functionality described. When one or more modules 210 are configured together with the functionality described as defined herein, they result in novel hardware.

[0037] In one implementation, module 210 may include, for example, a communication module 220, a channel value determination module 222, a PRB size determination module 224, and other modules 226. Such modules may be represented as a single module or a combination of different modules. In one implementation, data 208 may include, for example, communication data 212, channel data 214, PRB size data 216, and other data 218.

[0038] In one embodiment, the communication module 220 may be configured to transmit the CSI-RS and PRB group size to the UE 104. Here, the communication module 220 may be configured to transmit the CSI-RS and PRB group size when the BS-DU 102 establishes a connection with the UE 104 on a radio channel. The CSI-RS is a reference signal used to perform CSI prediction. The CSI-RS is used for channel sounding purposes and is used to measure the characteristics of the radio channel so that the channel can utilize the correct modulation, code rate, beamforming, etc. The PRB group size represents the number of PRBs used to perform CSI prediction. The BS-DU 102 configures the PRB group size based on the channel characteristics of the radio channel. The channel characteristics affect the PRB group size that should be used for CSI prediction.

[0039] In one embodiment, the communication module 220 transmits the PRB group size in a Radio Resource Control (RRC) reconfiguration message over the downlink (DL). In one example, the communication module 220 transmits an RRC reconfiguration message with a PRB group size of 4. In this case, the UE 104 performs CSI prediction for 4 PRBs. Referring to the flowchart 300 illustrated in Figure 3, the UE 104 is in an RRC connected state as shown in step 1. As shown in step 2, the communication module 220 transmits an RRC reconfiguration message to the UE 104, including the PRB group size. As shown in step 3, the communication module 220 transmits a CSI-RS to the UE 104. As shown in step 4, the UE 104 performs CSI prediction using the PRB group size.

[0040] Returning to Figure 2, in one embodiment, the communication module 220 may be configured to receive compressed CSI feedback from the UE 104 in response to the transmission of CSI-RS. The CSI feedback is generated by the UE 104 based on the CSI-RS received from the BS-DU 102. Furthermore, the CSI feedback is compressed by the UE 104 based on the channel parameters of one or more radio channels. The one or more channel parameters may include channel selectivity, angular velocity, etc. The compressed CSI feedback may contain only specific portions of data useful for analyzing the radio channels. For example, suppose the radio channel is a frequency-flat channel. For frequency-flat channels, only specific portions of the CSI feedback may contain useful data. In such cases, the frequency granularity of reporting can be reduced over time for frequency-flat channels. In another example, the spatial granularity of reporting can be changed based on the angular spread in the radio channel. This ensures that uplink overhead in the wireless communication network is reduced without losing channel information. Furthermore, since the CSI feedback channel has strict error requirements, reducing the overhead significantly reduces the uplink resources required for transmission. Returning to Figure 3 again, in step 5, the communication module 220 receives the compressed CSI feedback from UE 104 over the physical uplink control channel (PUCCH). Returning to Figure 2, the CSI-RS, compressed CSI feedback, and PRB group size may be stored as communication data 212 in memory 204.

[0041] In one embodiment, the communication module 220 may be configured to periodically receive ground truth CSI-RS from the UE 104. The communication module 220 may periodically receive ground truth CSI-RS from the UE 104 after initially transmitting the CSI-RS and PRB group size. In one embodiment, the communication module 220 may be configured to receive ground truth CSI-RS from the UE 104 at predetermined time intervals. The ground truth CSI-RS comprises actual CSI-RS samples received by the UE 104 from the BS-DU 102. The communication module 220 receives ground truth CSI-RS so that the channel selectivity parameters of the radio channel can be monitored. Monitoring the radio channel helps determine whether the PRB group size needs to be updated based on the channel selectivity parameters of the radio channel. This disclosure provides a procedure for receiving ground truth CSI-RS from the UE 104 to dynamically update or optimize the PRB group size based on the channel selectivity parameters. This ensures increased accuracy when performing CSI prediction and reporting in UE104. Referring again to Figure 3, as shown in step 6, the communication module 220 receives ground truth CSI-RS from UE104 on PUCCH. Returning to Figure 2, the ground truth CSI-RS may be stored as communication data 212 in memory 204.

[0042] In one embodiment, the channel value determination module 222 is configured to receive communication data 212 from the communication module 220. Furthermore, the channel value determination module 222 is configured to determine the values ​​of one or more channel selectivity parameters of the radio channel based on the ground truth CSI-RS received from the UE 104. The one or more channel selectivity parameters may include at least one of the frequency selectivity, spatial selectivity, and time selectivity of the radio channel. The channel value determination module 222 may be configured to determine amplitude fluctuations across at least one of the frequency domain, spatial domain, and time domain. In one example, the channel value determination module 222 may determine high frequency selectivity for a frequency-flat channel. The values ​​of one or more channel selectivity parameters may be stored as channel data 214 in the memory 204.

[0043] In one embodiment, the PRB size determination module 224 may be configured to receive channel data 214 from the channel value determination module 222. Furthermore, the PRB size determination module 224 may be configured to determine the updated PRB group size based on changes in the values ​​of one or more channel selectivity parameters. The PRB group size is affected by the channel selectivity parameters of one or more radio channels. Since the characteristics of radio channels can change frequently over time, it is necessary to update the PRB group size used for CSI prediction. The PRB size determination module 224 may determine whether the PRB group size needs to be updated based on one or more channel selectivity parameters. The PRB size determination module 224 may determine the updated PRB group size based on one or more channel selectivity parameters. In one example, for a frequency flat channel, the frequency selectivity may be high. Suppose the initial PRB size transmitted to UE104 is 4. In such a case, since the PRB group size is inversely proportional to the frequency selectivity of the radio channel, the PRB size determination module 224 may determine the updated PRB group size to be "2". Referring again to Figure 3, in step 7, the channel value determination module 222 may determine the updated PRB group size based on the changes in the values ​​of one or more selectivity parameters determined from the ground truth CSI-RS. Returning to Figure 2, the updated PRB group size may be stored as PRB size data 216 in memory 204.

[0044] In one embodiment, the communication module 220 may be configured to receive PRB size data 216 from the PRB size determination module 224. Furthermore, the communication module 220 may be configured to transmit the updated PRB group size to the UE 104. In one embodiment, the communication module 220 may transmit a request indicating the updated PRB group size to the BS-CU 106. Furthermore, the communication module 220 may receive an acknowledgment from the BS-CU 106. In such a case, the BS-CU 106 transmits an RRC reconfiguration message indicating the updated PRB group size to the UE 104. In another embodiment, the communication module 220 transmits the updated PRB group size to the UE 104 in a media access control message. This ensures reduced signaling in the wireless network. In this disclosure, the PRB group size is dynamically updated based on channel characteristics. This ensures the accuracy of the CSI prediction performed in the UE 104.

[0045] Other data 218 may store data including temporary data and temporary files generated by one or more modules 210 to perform various functions of BS-DU102. Other data 218 may be stored in memory 204. One or more modules 210 may include other modules 226 to perform various functions of BS-DU102.

[0046] Figure 4 shows an exemplary flowchart illustrating method steps for reporting CSI feedback in a wireless network according to some embodiments of the present disclosure. As illustrated in Figure 4, Method 400 may comprise one or more steps. Method 400 may be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions that perform a particular function or implement a particular abstract data type.

[0047] The order in which Method 400 is described is not intended to be interpreted as restrictive, as any number of described Method blocks can be combined in any order to implement the Method. In addition, individual blocks may be removed from the Method without deviating from the scope of the subject matter described herein. Furthermore, the Method can be implemented in any suitable hardware, software, firmware, or combination thereof.

[0048] In step 401, the CSI-RS and PRB group sizes are transmitted to UE104. The CSI-RS and PRB group sizes are transmitted when BS-DU102 establishes a connection with UE104 on a wireless or radio channel. The PRB group size is transmitted on the downlink (DL) in a radio resource control (RRC) reconfiguration message.

[0049] In step 402, ground truth CSI-RS may be received periodically from UE104. Ground truth CSI-RS may be received periodically from UE104 after the initial transmission of CSI-RS and PRB group size. In one embodiment, ground truth CSI-RS may be received from UE104 at predetermined time intervals. Ground truth CSI-RS comprises actual CSI-RS samples received by UE104 from BS-DU102.

[0050] In step 403, the values ​​of one or more channel selectivity parameters of the radio channel are determined based on the ground truth CSI-RS received from UE104. The one or more channel selectivity parameters may comprise at least one of the frequency selectivity, spatial selectivity, and time selectivity of the radio channel. Amplitude variations across at least one of the frequency domain, spatial domain, and time domain are determined.

[0051] In step 404, the updated PRB group size is determined based on the change in the value of one or more channel selectivity parameters. The PRB group size is affected by the channel selectivity parameters of one or more radio channels. Since the characteristics of radio channels can change frequently over time, the PRB group size used for CSI prediction needs to be updated. The updated PRB group size may be determined based on one or more channel selectivity parameters.

[0052] In step 405, the updated PRB group size is sent to UE104. In one embodiment, a request indicating the updated PRB group size is sent to BS-CU106. Further confirmation is received from BS-CU106. In this case, BS-CU106 sends an RRC reconfiguration message indicating the updated PRB group size to UE104. In another embodiment, the updated PRB group size is sent to UE104 in a media access control message.

[0053] [Computer System] Figure 5 illustrates a block diagram of an exemplary computer system 500 for implementing an embodiment consistent with the present disclosure. In one embodiment, the computer system 500 may be used to implement the BS-DU102. In one embodiment, the computer system 500 may communicate with the UE524 and BS-CU526 over a communication network 518. The computer system 500 may include a central processing unit 504 (also referred to as the "CPU" or "processor"). The processor 504 may include at least one data processor. The processor 504 may include dedicated processing units such as an integrated system (bus) controller, a memory management control unit, a floating-point unit, a graphics processing unit, and a digital signal processing unit.

[0054] The processor 504 may be used for communication with one or more input / output (I / O) devices (not shown) via the I / O interface 502. The I / O interface 502 may utilize (but not limited to) communication protocols / methods such as audio, analog, digital, mono, RCA, stereo, IEEE (Institute of Electrical and Electronics Engineers)-1394, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), HDMI (high-definition multimedia interface), radio frequency (RF) antenna, S-Video, VGA, IEEE 802.n / b / g / n / x, Bluetooth, and cellular (e.g., CDMA (code-division multiple access), High Speed ​​Packet Access (HSPA+), GSM (global system for mobile communications), Long-Term Evolution (LTE), WiMAX, etc.).

[0055] Using the I / O interface 502, the computer system 500 may communicate with one or more I / O devices. For example, the input device 520 may be an antenna, keyboard, mouse, joystick, (infrared) remote control, camera, card reader, fax machine, dongle, biometric reader, microphone, touchscreen, touchpad, trackball, stylus, scanner, storage device, transceiver, video device / source, sensor, etc. The output device 522 may be a printer, fax machine, video display (e.g., cathode ray tube (CRT), liquid crystal display (LCD), light-emitting diode (LED), plasma, plasma display panel (PDP), organic light-emitting diode display (OLED), etc.), audio speaker, etc.

[0056] The processor 504 may be in communication with the communication network 518 via the network interface 506. The network interface 506 may communicate with the communication network 518. The network interface 506 may utilize connection protocols including, but not limited to, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), Transmit Control Protocol / Internet Protocol (TCP / IP), Token Ring, IEEE 802.11a / b / g / n / x, etc. The communication network 518 may include, but is not limited to, direct interconnects, local area networks (LANs), wide area networks (WANs), wireless networks (e.g., using wireless application protocols), the Internet, etc. The network interface 506 may utilize connection protocols including, but not limited to, Direct Connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), Transmit Control Protocol / Internet Protocol (TCP / IP), Token Ring, IEEE 802.11a / b / g / n / x, Bluetooth Mesh, Zigbee, etc.

[0057] The communication network 518 includes, but is not limited to, direct interconnects, e-commerce networks, peer-to-peer (P2P) networks, local area networks (LANs), wide area networks (WANs), wireless networks (e.g., using wireless application protocols), the Internet, Wi-Fi, etc. The first network and the second network may be dedicated or shared networks representing a relationship between different types of networks, using various protocols to communicate with each other, such as hypertext transfer protocol (HTTP), transmit control protocol / Internet protocol (TCP / IP), wireless application protocol (WAP), etc. Furthermore, the first network and the second network may include various network devices, including routers, bridges, servers, computing devices, storage devices, etc.

[0058] In some embodiments, the processor 504 may be placed in communication with memory 510 (e.g., RAM, ROM, etc. / not shown in Figure 5) via a storage interface 508. The storage interface 508 may be connected to memory 510, including but not limited to memory drives and removable disk drives, using connection protocols such as SATA (serial advanced technology attachment), IDE (Integrated Drive Electronics), IEEE-1394, USB (Universal Serial Bus), Fibre Channel, and SCSI (Small Computer Systems Interface). The memory drive may further include drums, magnetic disk drives, magneto-optical drives, optical drives, RAID (Redundant Array of Independent Discs), solid-state memory devices, and solid-state drives.

[0059] The memory 510 may store a set of program or database components including, but not limited to, a user interface 512, an operating system 514, a web browser 516, and the like. In some embodiments, the computer system 500 may store user / application data such as data, variables, records and the like as described in the present disclosure. Such databases may be Oracle R or Sybase R etc., and may be implemented as a fault-tolerant, relational, scalable, secure database.

[0060] The operating system 514 may facilitate resource management and operation of the computer system 500. Examples of operating systems include APPLE MACINTOSH R OS X, UNIX R , UNIX-like system distributions (e.g., BERKELEY SOFTWARE DISTRIBUTION TM (BSD), FREEBSD TM , NETBSD TM , OPENBSD TM and the like), LINUX DISTRIBUTIONS TM (e.g., RED HAT TM , UBUNTU TM , KUBUNTU TM and the like), IBM TM OS / 2, MICROSOFT TM WINDOWS TM (XP TM , VISTA TM / 7 / 8, 10, etc.), APPLE R IOS TM , GOOGLE R ANDROID TM , BLACKBERRY R OS, and the like, but are not limited thereto.

[0061] In some embodiments, the computer system 500 may implement a web browser 516 storage program component. The web browser 516 may be, for example, Microsoft R INTERNET EXPLORER TM , GOOGLE R CHROME TM0 MOZILLA R FIREFOX TM APPLE R SAFARI TM Other hypertext viewing applications may also be used. Secure web browsing may be provided using Secure Hypertext Transport Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), etc. The web browser 516 uses AJAX TM DHTML TM ADOBE R FLASH TM , JAVASCRIPT TM , JAVA TM Facilities such as Application Programming Interfaces (APIs) may be used. In some embodiments, the computer system 500 may implement a mail server (not shown) storage program component. The mail server may be an Internet mail server such as Microsoft Exchange. The mail server is an ASP TM、 ACTIVEX TM ANSI TM C++ / C#, Microsoft R .NET TM CGI SCRIPTS TM , JAVA TM , JAVASCRIPT TM , PERL TM , PHP TM PYTHON TM WEBOBJECTS TMYou may also use facilities such as the following. The mail server uses Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), and Microsoft R Communication protocols such as Exchange, Post Office Protocol (POP), and Simple Mail Transfer Protocol (SMTP) may be used. In some embodiments, the computer system 500 may implement a mail client storage program component. The mail client (not shown) is APPLE R MASTER TM MICROSOFT R ENTOURAGE TM MICROSOFT R OUTLOOK TM MOZILLA R THUNDERBIRD TM Other email viewing applications are also acceptable.

[0062] Furthermore, one or more computer-readable storage media may be used to implement embodiments consistent with this disclosure. Computer-readable storage media represent any type of physical memory that may store information or data that can be read by a processor. Thus, computer-readable storage media may store instructions for execution by one or more processors, including instructions for causing a processor to perform steps or stages consistent with the embodiments described herein. The term “computer-readable media” should be understood to include tangible items and exclude carrier waves and transient signals; i.e., non-transient. Examples include random-access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard drives, compact disk read-only memory (CD-ROM), digital video discs (DVDs), flash drives, disks, and any other known physical storage media.

[0063] Furthermore, one or more computer-readable storage media may be used to implement embodiments consistent with the present disclosure. The computer-readable storage media represents any type of physical memory that may store information or data that can be read by a processor. Thus, the computer-readable storage media may store instructions for execution by one or more processors, including instructions for causing a processor to perform steps or stages consistent with the embodiments described herein. The term “computer-readable media” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transient. Examples include random-access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard drives, CD (Compact Disc) ROMs, DVDs, flash drives, disks, and any other known physical storage media.

[0064] The terms "one embodiment," "embodiment," "multiple embodiments," "this embodiment," "multiple embodiments," "one or more embodiments," "several embodiments," and "one embodiment" all mean "one or more (but not all) embodiments of the present invention" unless otherwise specified.

[0065] The terms "includes," "equipped with," and "possess," and their variations, unless otherwise specified, mean "includes, but is not limited to."

[0066] The enumerated listing of items does not imply that any or all of the items are mutually exclusive unless otherwise specified. The terms "a," "an," and "the" mean "one or multiple" unless otherwise specified.

[0067] The description of one embodiment having several components that can communicate with one another does not imply that all such components are essential. On the contrary, various optional components are described in order to illustrate a wide range of possible embodiments of the present invention.

[0068] When a single device or article is described herein, it is readily apparent that multiple devices / articles (whether working together or not) may be used in place of the single device / article. Similarly, when multiple devices or articles (whether working together or not) are described herein, it is readily apparent that a single device / article may be used in place of multiple devices or articles, and that a different number of devices / articles may be used in place of the number of devices or programs indicated. The functions and / or features of a device may instead be embodied by one or more other devices not explicitly described as having such functions / features. For this reason, other embodiments of the present invention may not include the device itself.

[0069] The example operation shown in Figure 4 illustrates that specific events occur in a particular order. In alternative embodiments, specific operations may be performed in a different order, modified, or eliminated. Furthermore, steps may be added to the logic described above, and it may still conform to the embodiments described. Furthermore, the operations described herein may occur sequentially, or certain operations may be processed in parallel. Additionally, the operations may be performed by a single processing unit or by distributed processing units.

[0070] Finally, the language used herein has been selected primarily for readability and instructional purposes, and not to outline or define the subject matter of the invention. Accordingly, the scope of the invention is not limited by this detailed description and is intended to be limited by the claims to be issued pursuant to this application. Accordingly, the disclosure of embodiments of the invention is intended to be illustrative and not to limit the scope of the invention as presented in the following claims.

[0071] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will also be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for illustrative purposes only and are not intended to be limiting; the true scope is shown by the following claims.

Claims

1. A base station (BS) distributed unit (DU), Transmitting a channel status information reference signal (CSI-RS) and a physical resource block (PRB) group size to a user equipment (UE), wherein the UE uses at least the PRB group size to perform CSI prediction of the radio channel between the UE and the BS-DU. Determining a change in the value of one or more channel selectivity parameters of the aforementioned wireless channel, The updated PRB group size is determined based on the changes in the values ​​of one or more of the aforementioned channel selectivity parameters. Transmitting the updated PRB group size to the UE, wherein the UE uses at least the updated PRB group size to perform the CSI prediction for the radio channel. BS-DU is configured to run.

2. The BS-DU according to claim 1, configured to receive compressed CSI feedback from the UE in response to the transmission of the CSI-RS, wherein the compressed CSI feedback is generated by the UE based on one or more channel parameters of the radio channel.

3. The BS-DU according to claim 1, wherein the one or more channel selectivity parameters comprise at least one of the frequency selectivity, spatial selectivity, and temporal selectivity of the radio channel.

4. A request indicating the updated PRB group size is sent to the base station aggregation unit (BS-CU), In response to the aforementioned request, the BS-CU receives confirmation, and the BS-CU transmits a radio resource control (RRC) reconfiguration message indicating the updated PRB group size to the UE. The BS-DU according to claim 1, configured to transmit the updated PRB group size to the UE.

5. The BS-DU according to claim 1, wherein the updated PRB group size is configured to be transmitted to the UE in a media access control message.

6. A base station (BS) distributed unit (DU) transmits a channel status information reference signal (CSI-RS) and a physical resource block (PRB) group size to a user equipment (UE), wherein the UE uses at least the PRB group size to perform a CSI prediction of the radio channel between the UE and the BS-DU. The BS-DU determines the value of one or more channel selectivity parameters of the wireless channel, The BS-DU determines the updated PRB group size based on the change in the value of one or more channel selectivity parameters, The BS-DU transmits the updated PRB group size to the UE, the UE using at least the updated PRB group size to perform the CSI prediction for the radio channel. A method for providing this.

7. The method according to claim 6, wherein, in response to the transmission of the CSI-RS, compressed CSI feedback is received from the UE, the compressed CSI feedback being generated by the UE based on one or more channel parameters of the radio channel.

8. The method according to claim 6, wherein the one or more channel selectivity parameters comprise at least one of the frequency selectivity, spatial selectivity, and temporal selectivity of the radio channel.

9. Sending the updated PRB group size to the UE means A request indicating the updated PRB group size is sent to the base station aggregation unit (BS-CU), In response to the aforementioned request, the BS-CU receives confirmation, and the BS-CU transmits a radio resource control (RRC) reconfiguration message indicating the updated PRB group size to the UE. The method according to claim 6, comprising:

10. The method according to claim 6, wherein the updated PRB group size is transmitted to the UE in a media access control message.

11. Transmitting a Channel Status Information Reference Signal (CSI-RS) and a Physical Resource Block (PRB) group size to a user equipment (UE), wherein the UE uses at least the PRB group size to perform CSI prediction of the radio channel between the UE and the base station (BS) distributed unit (DU), Determining the value of one or more channel selectivity parameters of the aforementioned wireless channel, The updated PRB group size is determined based on the changes in the values ​​of one or more of the aforementioned channel selectivity parameters. Transmitting the updated PRB group size to the UE, wherein the UE uses at least the updated PRB group size to perform the CSI prediction for the radio channel. A non-temporary computer-readable medium containing instructions for performing an operation that includes [a specific feature / function].

12. The medium according to claim 11, wherein the operation involves receiving compressed CSI feedback from the UE in response to a transmission of the CSI-RS, the compressed CSI feedback being generated by the UE based on one or more channel parameters of the radio channel.

13. The medium according to claim 11, wherein the one or more channel selectivity parameters comprise at least one of the frequency selectivity, spatial selectivity, and temporal selectivity of the radio channel.

14. Sending the updated PRB group size to the UE means A request indicating the updated PRB group size is sent to the base station aggregation unit (BS-CU), In response to the aforementioned request, the BS-CU receives confirmation, and the BS-CU transmits a radio resource control (RRC) reconfiguration message indicating the updated PRB group size to the UE. The medium according to claim 11, comprising:

15. The updated PRB group size is transmitted to the UE in a media access control message, according to claim 11.

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