Channel state information (CSI) feedback reporting in wireless networks

Abstract

An embodiment of the present disclosure discloses a base station (BS)-distributed unit (DU) (102). A BS-DU (102) 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) (104), where the UE (104) performs CSI prediction of a wireless channel between the UE (104) and the BS-DU (102) using the PRB group size, periodically receives terrestrial live CSI-RS from the UE (104), determines values of one or more channel selectivity parameters of the wireless channel based on the terrestrial live CSI-RS received from the UE (104), and transmits the determined values to the UE (104). An updated PRB group size is determined based on values of the one or more channel selectivity parameters, and the updated PRB group size is transmitted to the UE (104), where the UE (104) performs CSI prediction of the wireless channel using the updated PRB group size.

Description

Cross Reference to Related Applications

[0001] This application claims the benefit of Indian Provisional Application No. 202341052059, filed August 2, 2023, entitled “METHOD AND SYSTEM FOR TRANSMITTING CHANNEL STATE INFORMATION (CSI) FEEDBACK WITH VARYING GRANULARITY,” and Indian Application No. 202341052059, filed December 15, 2023, entitled “CHANNEL STATE INFORMATION (CSI) FEEDBACK REPORTING IN WIRELESS NETWORKS,” the entire contents of both of which are expressly incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to channel state information (CSI) feedback reporting in wireless networks. BACKGROUND

[0003] In wireless communication networks, such as in 5thGeneration New Radio (5G NR), channel state information (CSI) describes the channel properties of a radio channel or a communication link. For example, CSI describes properties of signal propagation, such as scattering, fading, power attenuation, etc. Channel state information reference signals (CSI-RS) are reference signals (RS) used in the downlink (DL) direction. In this context, CSI-RS are used for the purpose of channel sounding and are used to measure the characteristics of the radio channel so that the channel is utilized with the correct modulation, code rate, beamforming, etc. Typically, a base station (e.g., a gNodeB or gNB) associated with a wireless communication network transmits CSI-RS in the DL in a periodic or aperiodic manner. A user equipment (UE) performs CSI prediction in response to the CSI-RS received from the base station. In one example, the UE can measure CSI such as transmission rank, precoder matrix indicator, channel quality indicator, etc.

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

[0005] Further, with the advancement in communication technology, there exists an advanced technique of using artificial intelligence (AI) / machine learning (ML) based CSI estimation and prediction. In this technique, each of the plurality of UEs in the wireless communication network transmits CSI feedback along with the assistance information to the base station for enhanced CSI feedback.

[0006] The information disclosed in the Background section of this disclosure is only for the purpose of enhancing the understanding of the general background of the application and should not be taken as admitting that this information is prior art with respect to the present application. SUMMARY

[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 a CSI prediction of a wireless channel between the UE and the BS-DU. Further, the BS-DU periodically receives a live CSI-RS from the UE. The BS-DU determines a value of one or more channel selectivity parameters of the wireless channel based on the live CSI-RS received from the UE. Further, the BS-DU determines an updated PRB group size based on a change in the value 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 the CSI prediction of the wireless channel.

[0008] In one embodiment, the present disclosure discloses a method. The method includes 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 a CSI prediction of a wireless channel between the UE and the BS-DU. Further, the method includes periodically receiving a live CSI-RS from the UE. The method includes determining a value of one or more channel selectivity parameters of the wireless channel based on the live CSI-RS received from the UE. Further, the method includes determining an updated PRB group size based on a change in the value of the one or more channel selectivity parameters. Thereafter, the method includes transmitting the updated PRB group size to the UE. The UE uses the updated PRB group size to perform the CSI prediction of the wireless channel.

[0009] In one embodiment, a non-transitory computer-readable medium is disclosed. The non-transitory computer-readable medium includes instructions for performing operations comprising sending a channel state information reference signal (CSI-RS) and a physical resource block (PRB) group size to a user equipment (UE). The UE performs a CSI prediction of a wireless channel between the UE and a BS-DU considering the configured PRB group size. Further, the operations comprise periodically receiving a live CSI-RS from the UE. The operations comprise determining values of one or more channel selectivity parameters of the wireless channel based on the live CSI-RS received from the UE. Further, the operations comprise determining an updated optimal PRB group size based on the changed values of the one or more channel selectivity parameters. Thereafter, the operations comprise sending the updated PRB group size to the UE. The UE performs the CSI prediction of the wireless channel using the updated PRB group size.

[0010] The above summary is illustrative only and is not intended to be limiting in any way. Still other aspects, embodiments, and features relating to the aspects and embodiments described herein can be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings, or can be learned by practice of the technology. BRIEF DESCRIPTION OF DRAWINGS

[0011] The novel features of the present disclosure are set forth with particularity in the appended claims. However, the present disclosure itself, further goals, advantages, and objects, as well as additional inventive features thereof, will be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings, of which:

[0012] Figure 1 FIGURE 1 illustrates an exemplary environment for reporting channel state information (CSI) in a wireless network, in accordance with some embodiments of the present disclosure;

[0013] Figure 2 FIGURE 2 illustrates a detailed diagram of a base station (BS)-distributed unit (DU) in a wireless network, in accordance with some embodiments of the present disclosure;

[0014] Figure 3 FIGURE 3 shows an exemplary flow diagram for reporting CSI in a wireless network, in accordance with some embodiments of the present disclosure;

[0015] Figure 4 FIGURE 4 shows an exemplary flow diagram illustrating method steps for reporting CSI in a wireless network, in accordance with some embodiments of the present disclosure; and

[0016] Figure 5 FIGURE 5 shows a block diagram of a general computing system for reporting CSI in a wireless network, in accordance with embodiments of the present disclosure.

[0017] Those skilled in the art will appreciate that any flowchart, flow diagram, state transition diagram, pseudocode, and / or other representation of a system embodied in this document is a conceptual view of the processes represented therein. Similarly, it will be understood that any flowchart, flow diagram, state transition diagram, pseudocode, and / or other representation of a process is a conceptual view of the processes represented therein and that the processes can be embodied in computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown. DETAILED DESCRIPTION

[0018] In this document, the term “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation of the subject matter described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations.

[0019] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0020] The terms “comprise,” “comprising,” or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of components or steps does not include only those components or steps but can include other components or steps not expressly listed or inherent to such process, method, article, or apparatus. In other words, without further restriction, one or more elements of a system or apparatus preceded by “comprising” or “comprises” does not exclude the presence of additional elements or additional elements of the system or apparatus.

[0021] Channel state information (CSI) describes channel properties of a radio channel or communication link in a wireless communication network. For example, CSI describes properties of signal propagation, such as scattering, fading, power attenuation, etc. Channel state information reference signals (CSI-RS) are reference signals (RS) used in the downlink (DL) direction. In this document, CSI-RS are used for channel sounding purposes and are used to measure properties of a radio channel so that the channel is utilized with the correct modulation, code rate, beamforming, etc. Typically, a base station (e.g., a gNodeB or gNB) associated with a wireless communication network transmits CSI-RS in the DL in a periodic or aperiodic manner. A user equipment (UE) performs CSI prediction in response to the CSI-RS received from the base station. In one example, the UE can measure CSI such as transmission rank, precoder matrix indicator, channel quality indicator, etc.

[0022] The UE performs CSI prediction based on the CSI-RS samples actually received in the DL from the base station. Notably, CSI prediction is not performed for each individual physical resource block (PRB), but for a group of PRBs. The size of the PRB can be different. For example, CSI prediction can be performed for 2 PRBs, 4 PRBs, 8 PRBs, etc. In this context, the size of the group of PRBs directly depends on the selectivity of the radio channel. For example, high frequency selectivity implies a smaller group of PRB size, while lower frequency selectivity implies a larger group of PRB size.

[0023] The size of the PRB to be used for CSI prediction is provided to the UE through radio resource control (RRC) signaling. In conventional systems, after the size of the PRB is initially provided to the UE, there is no procedure defined to dynamically update or optimize the PRB size based on the selectivity of the radio channel. The size of the PRB has an impact on the performance of the CSI prediction at the UE. Therefore, there is a need to update or optimize the size of the PRB based on the selectivity of the radio channel.

[0024] Further, with advancements in communication technology, there are advanced techniques of using artificial intelligence (AI) / machine learning (ML) based CSI estimation and prediction. In such techniques, each of the plurality of UEs in the wireless communication network transmits the CSI feedback along with the assistance information to the base station for enhanced CSI feedback. However, this amounts to huge uplink overhead as a large number of UEs communicate the enhanced CSI feedback to the base station in the wireless communication network.

[0025] The present disclosure provides a base station (BS)-distributed unit (DU) and a method to overcome the above-mentioned limitations. In the present disclosure, the BS-DU periodically receives live ground CSI-RS from the user equipment (UE) after initially transmitting the CSI-RS and the group of PRB size. The BS-DU monitors the channel selectivity parameters of the wireless channel between the UE and the BS-DU based on the live ground CSI-RS. The BS-DU determines whether the group of PRB size needs to be updated based on the channel selectivity parameters of the wireless channel. Accordingly, the BS-DU updates the group of PRB size and transmits the updated group of PRB size to the UE. The UE performs CSI prediction using the updated group of PRB size. Accordingly, the present disclosure provides a procedure to dynamically update or optimize the group of PRB size based on the channel selectivity parameters. This ensures improved accuracy of the CSI prediction and reporting at the UE.

[0026] Notably, the CSI-RS is predicted at the UE and the CSI feedback information is sent to the gNB with varying PRB granularity. The prediction of the CSI feedback with different PRB granularity involves dynamically estimating the characteristics of the channel. By using finer granularity during periods of fast channel variation or high mobility, and coarser granularity when the channel conditions are stable or resources are limited, the wireless communication network optimizes resource utilization and efficiently adapts its transmission parameters. This dynamic approach enhances spectral efficiency, reduces interference, and increases overall network capacity, ensuring reliable and high-quality communication services for users in a wireless environment.

[0027] In the present disclosure, the UE generates the CSI feedback based on the channel parameters of the wireless channel. Therefore, the reported PRB granularity of the CSI feedback can be reduced based on the channel parameters, and the compressed CSI feedback can be sent to the BS-DU. This ensures reduced uplink overhead in the wireless communication network without losing channel information. Further, the CSI feedback channel has very stringent error requirements, and therefore reducing the overhead significantly reduces the uplink resources for transmission.

[0028] Figure 1 An exemplary environment 100 reporting CSI feedback in a wireless network is illustrated in accordance with an embodiment of the present disclosure. The exemplary environment 100 includes a base station (BS) - distributed unit (DU) 102, a user equipment (UE) 104, and a base station (BS) - central unit (DU) 106. The BS-DU 102 and the BS-CU 106 are part of a base station or a gNodeB or gNB. The description of the present disclosure is explained considering only the fifth generation (5G) network. However, the present disclosure is applicable to any type of network, such as a fourth generation (4G) network, a 5G network, and the like. In the 5G network, the gNB functions as a 5G base station, responsible for 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, connection control, and the like. The 5G core (5GC) provides core network functionality, facilitates scalability, and supports a wide variety of services and applications. Various functional nodes, such as the access and mobility management function (AMF), the session management function (SMF), and the user plane function (UPF), are part of the 5GC.

[0029] In a 5G network, a base station is split into three different components, a centralized unit (CU) (referred to as BS-CU 106 in this specification), a distributed unit (DU) (referred to as BS-DU 102 in this specification), and a remote radio unit (RU). The BS-CU 106 serves as a central intelligence that proficiently handles complex and centralized network functions. These functions include, but are not limited to, proficient radio resource management, efficient network control, and seamless coordination with the 5GC. The BS-DU 102 is responsible for managing data plane processing, including important tasks such as data transmission and reception with user equipment (UE) 104. The BS-DU 102 seamlessly interfaces with the BS-CU 106 through the Fl interface. The RU handles physical layer functions, housing antennas and radio transceivers that facilitate the actual transmission and reception of radio signals.

[0030] The UE 104 represents an end-user device that accesses services and applications through a wireless network. The UE 104 is configured to connect to the BS-DU 102 through a wireless network. Examples of the UE 104 include, but are not limited to, any device used by a user to communicate through a wireless network, such as, but not limited to, a mobile phone, a smartphone, a laptop, a wearable device, an Internet of Things (IoT), and the like.

[0031] The present disclosure relates to reporting CSI feedback in a wireless network. Channel state information (CSI) describes the channel properties of a radio channel or a communication link. For example, CSI describes the properties of signal propagation, such as scattering, fading, power attenuation, and the like. Channel state information reference signals (CSI-RS) are reference signals (RS) used in the downlink (DL) direction. In this document, the CSI-RS is used for the purpose of channel sounding and is used to measure the characteristics of the radio channel so that the channel is utilized with the correct modulation, code rate, beamforming, and the like. Typically, the BS-DU 102 transmits the CSI-RS in the DL in a periodic or aperiodic manner. The UE 104 performs CSI prediction in response to the CSI-RS received from the BS-DU 102. In one example, the UE 104 can measure CSI, such as transmission rank, precoder matrix indicator, channel quality indicator, and the like. The UE 104 performs CSI prediction for physical resource block (PRB) groups, such as 2 PRBs, 4 PRBs, and the like. A PRB is a resource block used for actual transmission / reception in a wireless network. In an example implementation, a PRB consists of twelve subcarriers on which transmission / reception is scheduled.

[0032] In the present disclosure, the BS-DU 102 is configured to transmit a CSI-RS and a PRB group size to the UE 104. The UE 104 performs CSI prediction of the wireless channel between the UE 104 and the BS-DU 102 for the configured PRB group size. In one example, the PRB group size can be four. In this case, the UE 104 performs the CSI prediction for 2 PRBs. The BS-DU 102 can configure the PRB group size based on the channel characteristics when establishing the initial connection with the UE 104. In the present disclosure, the BS-DU 102 periodically receives live floor CSI-RS from the UE 104. The live floor CSI-RS is received such that the BS-DU 102 can monitor the channel characteristics in a periodic manner and determine whether an update of the PRB group size is required based on the channel characteristics.

[0033] The BS-DU 102 determines values of one or more channel selectivity parameters of the wireless channel based on the live floor CSI-RS received from the UE 104. The one or more channel selectivity parameters can include at least one of a frequency selectivity, a spatial selectivity, and a time selectivity of the wireless channel. In one example, the BS-DU 102 can determine a rate of change of the amplitude of the signal transmitted over the wireless channel over time. The BS-DU 102 determines an updated PRB group size based on a change in the values of the one or more channel selectivity parameters. For example, the BS-DU 102 can determine a higher rate of change of the amplitude of the signal over time. The BS-DU 102 can determine that the PRB size needs to be updated. In this case, the updated PRB group size can be determined to be four. The BS-DU 102 can then transmit the updated PRB group size to the UE 104. In one embodiment, the BS-DU 102 can transmit a request indicating the updated PRB group size to the BS-CU 106. The BS-CU 106 can acknowledge the request and transmit a radio resource control (RRC) reconfiguration message indicating the updated PRB group size to the UE 104. In another embodiment, the BS-DU 102 can transmit the updated PRB group size to the UE 104 in a layer 2 medium access control message. The UE 104 uses the updated PRB group size to perform the CSI prediction of the wireless channel. Thus, the present disclosure enables dynamic update of the PRB group size based on the channel characteristics. Thus, the optimized PRB group size is considered and hence the accuracy of the CSI prediction performed at the UE 104 is improved.

[0034] In one embodiment, in response to transmission of the CSI-RS, the BS-DU 102 receives compressed CSI feedback from the UE 104. Herein, the UE 104 generates the compressed CSI feedback based on the ground truth CSI-RS and one or more channel parameters of the wireless channel. The UE 104 optimizes the granularity of reporting the CSI feedback based on the channel parameters. This ensures reduced uplink overhead in the wireless communication network without loss of channel information.

[0035] Figure 2 A detailed diagram of the BS-DU 102 in a wireless network is illustrated in accordance with some embodiments of the present disclosure. The BS-DU 102 can 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 can be communicatively coupled to the processor 206. The memory 204 stores instructions executable by the processor 206. The processor 206 can include at least one data processor for executing program components for performing user or system generated requests. The memory 204 can be communicatively coupled to the processor 206. The memory 204 stores instructions executable by the processor 206, which when executed can cause the processor 206 to send an updated PRB group size for CSI estimation and CSI feedback reporting. The I / O interface 202 is coupled to the processor 206 through which input signals or / and output signals are communicated. For example, the BS-DU 102 can send the updated PRB group size to the UE 104 via the I / O interface 202. In one embodiment, the BS-DU 102 can be implemented in various computing systems such as servers, network servers, cloud-based servers, and the like.

[0036] In one embodiment, the memory 204 can include one or more modules 210 and data 208. The one or more modules 210 can be configured to perform the steps of the present disclosure using the data 208. In one embodiment, each of the one or more modules 210 can be a hardware unit that can be external to the memory 204 and coupled with the BS-DU 102. As used herein, the term module 210 refers to an application specific integrated circuit (ASIC), an electronic circuit, a field programmable gate array (FPGA), a programmable system on a chip (PSoC), a combination of

[0037] In one implementation, the modules 210 can include, for example, a communication module 220, a channel value determination module 222, a PRB size determination module 224, and other modules 226. It will be understood that such above-described modules can be represented as a single module or a combination of different modules. In one implementation, the data 208 can 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 can be configured to send the CSI-RS and the PRB group size to the UE 104. Herein, the communication module 220 can be configured to send the CSI-RS and the PRB group size when the BS-DU 102 establishes a connection with the UE 104 over a wireless channel or 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 is utilized with the correct modulation, code rate, beamforming, etc. The PRB group size refers to 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 wireless channel. The channel characteristics affect the PRB group size that will be used for CSI prediction.

[0039] In one embodiment, the communication module 220 sends the PRB group size in a radio resource control (RRC) reconfiguration message over the downlink (DL). In one example, the communication module 220 sends an RRC reconfiguration message with a PRB group size of four. In this case, the UE 104 performs CSI prediction for 4 PRBs. Reference is made to Figure 3 In reference to the flowchart 300 illustrated in

[0040] In reference to the flowchart 300 illustrated in Figure 2In an embodiment, the communication module 220 can be configured to receive compressed CSI feedback from the UE 104 in response to transmission of the CSI-RS. The CSI feedback is generated by the UE 104 based on the CSI-RS received from the BS-DU 102. Further, the CSI feedback is compressed by the UE 104 based on one or more channel parameters of the wireless channel. The one or more channel parameters can include channel selectivity, angular spread, and the like. The compressed CSI feedback can include only specific data portions that are useful for analysis of the wireless channel. For example, consider that the wireless channel is a frequency flat channel. For a frequency flat channel, useful data can exist only in specific portions of the CSI feedback. In this case, the frequency granularity of the report can be reduced over time for the frequency flat channel. In another example, the spatial granularity of the report can be changed based on the angular spread in the wireless channel. This ensures reduced uplink overhead in the wireless communication network without loss of channel information. Further, the CSI feedback channel includes strict error requirements and hence reducing the overhead significantly reduces the uplink resources for transmission. Again, with reference to Figure 3 At step 5, the communication module 220 receives the compressed CSI feedback from the UE 104 over a physical uplink control channel (PUCCH). Again, with reference to Figure 2 The CSI-RS, the compressed CSI feedback, and the PRB group size can be stored in the memory 204 as the communication data 212.

[0041] In an embodiment, the communication module 220 can be configured to periodically receive live ground CSI-RS from the UE 104. After initially sending the CSI-RS and the PRB group size, the communication module 220 can periodically receive live ground CSI-RS from the UE 104. In an embodiment, the communication module 220 can be configured to receive the live ground CSI-RS from the UE 104 at predefined time intervals. The live ground CSI-RS includes actual CSI-RS samples received by the UE 104 from the BS-DU 102. The communication module 220 receives the live ground CSI-RS such that the channel selectivity parameters of the wireless channel can be monitored. The monitoring of the wireless channel facilitates determining whether the PRB group size needs to be updated based on the channel selectivity parameters of the wireless channel. The present disclosure provides a process of receiving the live ground CSI-RS from the UE 104 to dynamically update or optimize the PRB group size based on the channel selectivity parameters. This ensures improved accuracy of performing the CSI prediction and reporting at the UE 104. Again, with reference to Figure 3 The communication module 220 receives the live ground CSI-RS from the UE 104 over the PUCCH, as shown in step 6. Again, with reference to Figure 2 The live ground CSI-RS can be stored in the memory 204 as the communication data 212.

[0042] In an embodiment, the channel value determination module 222 is configured to receive the communication data 212 from the communication module 220. Further, the channel value determination module 222 is configured to determine the value of one or more channel selectivity parameters of the wireless channel based on the live over-the-air CSI-RS received from the UE 104. The one or more channel selectivity parameters can include at least one of the following: frequency selectivity, spatial selectivity, and temporal selectivity of the wireless channel. The channel value determination module 222 can be configured to determine the variation in amplitude over at least one of the frequency domain, the spatial domain, and the time domain. In one example, the channel value determination module 222 can determine a higher frequency selectivity for a frequency flat channel. The value of the one or more channel selectivity parameters can be stored in the memory 204 as the channel data 214.

[0043] In an embodiment, the PRB size determination module 224 can be configured to receive the channel data 214 from the channel value determination module 222. Further, the PRB size determination module 224 can be configured to determine an updated PRB group size based on a change in the value of the one or more channel selectivity parameters. The PRB group size is affected by the one or more channel selectivity parameters of the wireless channel. As the properties of the wireless channel can change frequently over time, it is necessary to update the PRB group size that is used for the CSI prediction. The PRB size determination module 224 can determine whether the PRB group size needs to be updated based on the one or more channel selectivity parameters. The PRB size determination module 224 can determine the updated PRB group size based on the one or more channel selectivity parameters. In one example, for a frequency flat channel, the frequency selectivity can be high. The initial PRB size to be transmitted to the UE 104 is considered to be four. In this case, the PRB size determination module 224 can determine the updated PRB group size ‘2’ as the PRB group size is inversely proportional to the frequency selectivity of the wireless channel. Again, referring to Figure 3 At step 7, the channel value determination module 222 can determine the updated PRB group size based on the change in the value of the one or more selectivity parameters determined from the live over-the-air CSI-RS. Again, referring to Figure 2 The updated PRB group size can be stored in the memory 204 as the PRB size data 216.

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

[0045] The other data 218 can store data (including temporary data and temporary files) generated by the one or more modules 210 for performing various functions of the BS-DU 102. The other data 218 can be stored in the memory 204. The one or more modules 210 can also include other modules 226 to perform miscellaneous functions of the BS-DU 102.

[0046] Figure 4 An exemplary flow diagram illustrating method steps for reporting CSI feedback in a wireless network is shown in accordance with some embodiments of the present disclosure. As Figure 4 As illustrated in the figure, the method 400 can include one or more steps. The method 400 can be described in the general context of computer-executable instructions. Generally, computer-executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, that perform particular functions or implement particular abstract data types.

[0047] The order in which the method 400 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method, Additionally, individual blocks can be deleted from the method without departing 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] At step 401, the CSI-RS and the PRB group size are transmitted to the UE 104. The CSI-RS and the PRB group size are transmitted when the BS-DU 102 establishes a connection with the UE 104 over a wireless channel or a radio channel. The PRB group size is transmitted in a radio resource control (RRC) reconfiguration message on the downlink (DL).

[0049] At step 402, ground truth CSI-RS can be received from the UE 104 periodically. The ground truth CSI-RS can be received from the UE 104 periodically after the initial transmission of the CSI-RS and the PRB group size. In one embodiment, the ground truth CSI-RS can be received from the UE 104 at a predefined time interval. The ground truth CSI-RS includes the actual CSI-RS samples received by the UE 104 from the BS-DU 102.

[0050] At step 403, values of one or more channel selectivity parameters of the wireless channel are determined based on the ground truth CSI-RS received from the UE 104. The one or more channel selectivity parameters can include at least one of a frequency selectivity, a spatial selectivity, and a temporal selectivity of the wireless channel. Variations in the amplitude over at least one of the frequency domain, the spatial domain, and the time domain are determined.

[0051] At step 404, an updated PRB group size is determined based on the change in the values of the one or more channel selectivity parameters. The PRB group size is affected by the one or more channel selectivity parameters of the wireless channel. Since the properties of the wireless channel can change frequently over time, it is necessary to update the PRB group size used for the CSI prediction. The updated PRB group size can be determined based on the one or more channel selectivity parameters.

[0052] At step 405, the updated PRB group size is transmitted to the UE 104. In one embodiment, a request indicating the updated PRB group size is transmitted to the BS-CU 106. Further, an acknowledgement is received from the BS-CU 106. In this case, the BS-CU 106 transmits an RRC reconfiguration message indicating the updated PRB group size to the UE 104. In another embodiment, the updated PRB group size is transmitted to the UE 104 in a medium access control message. Computer system

[0053] Figure 5 A block diagram illustrating an exemplary computer system 500 for implementing embodiments consistent with the present disclosure is shown. In one embodiment, the computer system 500 can be used to implement the BS-DU 102. In one embodiment, the computer system 500 can communicate with the UE 524 and the BS-CU 526 over the communication network 518. The computer system 500 can include a central processing unit 504 (also called a "CPU" or "processor"). The processor 504 can include at least one data processor. The processor 504 can include specialized processing units such as an integrated system (bus) controller, memory management control unit, floating point unit, graphics processing unit, digital signal processing unit, etc.

[0054] The processor 504 can be configured to communicate with one or more input / output (I / O) devices (not shown) via the I / O interface 502. The I / O interface 502 can employ communication protocols / methods such as, but not limited to, audio, analog, digital, monaural, 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), High-Definition Multimedia Interface (HDMI), radio frequency (RF) antenna, S- terminal, VGA, IEEE 802.n / b / g / n / x, Bluetooth, cellular (e.g., Code Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System for Mobile Communications (GSM), Long-Term Evolution (LTE), WiMax, etc.), etc.

[0055] Using the I / O interface 502, the computer system 500 can communicate with one or more I / O devices. For example, the input device 520 can be an antenna, a keyboard, a mouse, a joystick, an (infrared) remote control, a camera, a card reader, a fax machine, a dongle, a biometric reader, a microphone, a touchscreen, a touchpad, a trackball, a stylus, a scanner, a storage device, a transceiver, a video device / source, a sensor, etc. The output device 522 can be a printer, a fax machine, a 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.), an audio speaker, etc.

[0056] The processor 504 can be configured to communicate with a communication network 518 via the network interface 506. The network interface 506 can communicate with the communication network 518. The network interface 506 can employ connection protocols including, but not limited to, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), transmission control protocol / internet protocol (TCP / IP), token ring, IEEE 802.11a / b / g / n / x, etc. The communication network 518 can include, but is not limited to, direct interconnection, local area network (LAN), wide area network (WAN), wireless network (e.g., employing wireless application protocol), the Internet, etc. The network interface 506 can employ connection protocols including, but not limited to, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), transmission 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, a direct interconnection, an electronic commerce network, a peer-to-peer (P2P) network, a local area network (LAN), a wide area network (WAN), a wireless network (e.g., using wireless application protocol), the Internet, Wi-Fi, etc. The first network and the second network can be private networks or shared networks, which represent an association of different types of networks that communicate with each other using various protocols (e.g., hypertext transfer protocol (HTTP), transmission control protocol / Internet protocol (TCP / IP), wireless application protocol (WAP), etc.). Moreover, the first network and the second network can include various network devices, including routers, bridges, servers, computing devices, storage devices, etc.

[0058] In some embodiments, the processor 504 can communicate with the memory 510 (e.g., RAM, ROM, etc. not shown in FIG. 5) via a memory interface 508. The memory interface 508 can be connected to the memory 510, which includes, but is not limited to, memory drives, removable disk drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), Fibre Channel, small computer system interface (SCSI), etc. The memory drives can also include drums, disk drives, magneto-optical drives, optical drives, redundant array of independent disks (RAID), solid-state memory devices, solid-state drives, etc. Figure 5

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

[0060] The operating system 514 can facilitate management and operation of the resources of the computer system 500. Examples of operating systems include, but are not limited to, APPLE MACINTOSH R OS X, UNIX R , UNIX-like system distributions (e.g., BERKELEY SOFTWARE DISTRIBUTION TM (BSD), FREEBSD TM , NETBSD TM , OPENBSD TM , etc.), LINUX distributions (e.g., RED HAT TM , UBUNTU TM , etc.), MICROSOFT WINDOWS® OS, etc. TM ​, KUBUNTU TM , 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, etc.

[0061] In some embodiments, computer system 500 can implement program components stored by a web browser 516. Web browser 516 can be a hypertext viewing application such as MICROSOFT R INTERNET EXPLORER TM , GOOGLE R CHROME TM0 , MOZILLA R FIREFOX TM , APPLE R SAFARI TM , etc. Secure web browsing can be provided using secure hypertext transfer protocol (HTTPS), secure sockets layer (SSL), transport layer security (TLS), etc. Web browser 516 can utilize facilities such as AJAX TM , DHTML TM , ADOBE R FLASH TM , JAVASCRIPT TM , JAVA TM , application programming interfaces (APIs), etc. In some embodiments, computer system 500 can implement program components stored by a mail server (not shown). Mail server can be an internet mail server such as Microsoft Exchange, etc. Mail server can utilize facilities such as 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, WEB OBJECTS TM A mail server can utilize communication protocols such as Internet Message Access Protocol (IMAP), Message Application Programming Interface (MAPI), MICROSOFT Exchange, Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), or the like. In some embodiments, computer system 500 can implement a program component that stores mail messages in a mail client. The mail client (not shown) can be any email viewing application, such as APPLE R MAIL TM , MICROSOFT R ENTOURAGE TM , MICROSOFT R OUTLOOK TM , MOZILLA R THUNDERBIRD TM , and the like.

[0062] Further, one or more computer-readable storage media can be used to implement embodiments consistent with the present disclosure. A computer-readable storage medium refers to any physical memory of information by a processor readable that can be stored thereon. Thus, a computer-readable storage medium can store instructions for execution by one or more processors including instructions for causing a processor(s) to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" should be understood to encompass a tangible item and exclude a carrier wave and transient signals, i.e., is non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, non-volatile memory, hard drives, Compact Disc Read-Only Memory (CD-ROM), Digital Video Disk (DVD), flash drives, disks, and any other known physical memory storage medium.

[0063] Further, one or more computer-readable storage media can be used to implement embodiments consistent with the present disclosure. A computer-readable storage medium refers to any physical memory of information by a processor readable that can be stored thereon. Thus, a computer-readable storage medium can store instructions for execution by one or more processors including instructions for causing a processor(s) to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" should be understood to encompass a tangible item and exclude a carrier wave and transient signals, i.e., is non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, non-volatile memory, hard drives, CD (Compact Disc) ROM, DVD, flash drives, disks, and any other known physical memory storage medium.

[0064] The terms "a certain embodiment", "one embodiment”, “an embodiment”, and “embodiments” mean “one or more (but not all) embodiments of the invention”.

[0065] The terms "comprise", "comprising", "have", "having", "include", "including" and "contain", "containing", unless otherwise clearly specified, mean "including but not limited to".

[0066] Unless explicitly stated otherwise, an enumerated list of items does not imply that any or all of the items are mutually exclusive. Unless explicitly stated otherwise, the terms "a", "an", and "the" mean "one or more".

[0067] The description of an embodiment having multiple components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate various potential embodiments of the present invention.

[0068] Where a single device or article is described herein, it will be apparent that more than one device / article (whether or not they cooperate) can be used in place of a single device / article. Similarly, where multiple devices or articles are described herein (whether or not they cooperate), it will be apparent that a

[0069] Figure 4 The illustrated operations of FIG. 1 show certain events occurring in a certain order. In alternative embodiments, certain operations can be performed in a different order, modified or removed. Moreover, steps can be added to the above described logic and still conform to the described embodiments. Further, operations described herein can occur sequentially or certain operations can be processed in parallel. Yet further, operations can be performed by a single processing unit or by distributed processing units.

[0070] Finally, the language used in the specification has been principally selected for readability and instructional purposes and can not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the scope of the application is intended to be defined by the following claims, rather than the foregoing

[0071] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.

Claims

1. A base station (BS) – distributed unit (DU) (102) configured as follows: Sending a Channel State Information Reference Signal (CSI-RS) and a Physical Resource Block (PRB) group size to a User Equipment (UE) (104), wherein the UE (104) uses at least the PRB group size to perform CSI prediction of the radio channel between the UE (104) and the BS-DU (102); Determine the change in the value of one or more channel selectivity parameters of the wireless channel; The updated PRB group size is determined based on the change in the value of the one or more channel selectivity parameters; as well as The updated PRB group size is sent to the UE (104), wherein the UE (104) uses at least the updated PRB group size to perform the CSI prediction of the radio channel.

2. The BS-DU (102) according to claim 1 is configured as follows: In response to the transmission of the CSI-RS, compressed CSI feedback is received from the UE (104), wherein the compressed CSI feedback is generated by the UE (104) based on one or more channel parameters of the radio channel.

3. The BS-DU (102) according to claim 1, wherein the one or more channel selectivity parameters include at least one of the following: frequency selectivity, spatial selectivity, and time selectivity of the wireless channel.

4. The BS-DU (102) according to claim 1 is configured to send the updated PRB group size to the UE (104) by: Send a request to the base station-central unit (BS-CU) (106) indicating the updated PRB group size; and In response to the request, an acknowledgment is received from the BS-CU (106), wherein the BS-CU (106) sends a Radio Resource Control (RRC) reconfiguration message indicating the updated PRB group size to the UE (104).

5. The BS-DU (102) according to claim 1 is configured to send the updated PRB group size to the UE (104) in a media access control message.

6. A method comprising: The base station (BS)-distributed unit (DU) (102) sends a channel state information reference signal (CSI-RS) and a physical resource block (PRB) group size to the user equipment (UE) (104), wherein the UE (104) uses at least the PRB group size to perform CSI prediction of the radio channel between the UE (104) and the BS-DU (102); The values ​​of one or more channel selectivity parameters of the wireless channel are determined by the BS-DU (102); The updated PRB group size is determined by the BS-DU (102) based on changes in the values ​​of one or more channel selectivity parameters; and The updated PRB group size is sent from the BS-DU (102) to the UE (104), wherein the UE (104) uses at least the updated PRB group size to perform the CSI prediction of the radio channel.

7. The method of claim 6, comprising: In response to the transmission of the CSI-RS, compressed CSI feedback is received from the UE (104), wherein the compressed CSI feedback is generated by the UE (104) based on one or more channel parameters of the radio channel.

8. The method of claim 6, wherein the one or more channel selectivity parameters include at least one of the following: frequency selectivity, spatial selectivity, and time selectivity of the wireless channel.

9. The method of claim 6, wherein sending the updated PRB group size to the UE (104) comprises: Send a request to the base station-central unit (BS-CU) (106) indicating the updated PRB group size; and In response to the request, an acknowledgment is received from the BS-CU (106), wherein the BS-CU (106) sends a Radio Resource Control (RRC) reconfiguration message indicating the updated PRB group size to the UE (104).

10. The method of claim 6, wherein the updated PRB group size is sent to the UE (104) in a media access control message.

11. A non-transitory computer-readable medium comprising instructions for performing operations, the operations including: Sending a Channel State Information Reference Signal (CSI-RS) and a Physical Resource Block (PRB) group size to a User Equipment (UE) (104), wherein the UE (104) uses at least the PRB group size to perform CSI prediction of the radio channel between the UE (104) and the Base Station (BS)-Distributed Unit (DU) (102); Determine the values ​​of one or more channel selectivity parameters of the wireless channel; The updated PRB group size is determined based on the change in the value of the one or more channel selectivity parameters; as well as The updated PRB group size is sent to the UE (104), wherein the UE (104) uses at least the updated PRB group size to perform the CSI prediction of the radio channel.

12. The medium of claim 11, wherein the operation comprises: In response to the transmission of the CSI-RS, compressed CSI feedback is received from the UE (104), wherein the compressed CSI feedback is generated by the UE (104) based on one or more channel parameters of the radio channel.

13. The medium of claim 11, wherein the one or more channel selectivity parameters include at least one of the following: frequency selectivity, spatial selectivity, and time selectivity of the wireless channel.

14. The medium of claim 11, wherein sending the updated PRB group size to the UE (104) comprises: Send a request to the base station-central unit (BS-CU) (106) indicating the updated PRB group size; and In response to the request, an acknowledgment is received from the BS-CU (106), wherein the BS-CU (106) sends a Radio Resource Control (RRC) reconfiguration message indicating the updated PRB group size to the UE (104).

15. The medium of claim 11, wherein the updated PRB group size is sent to the UE (104) in a media access control message.

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