Techniques for spatial domain basis function refinement

Abstract

Techniques and devices for wireless communication are described. A user equipment (UE) may receive, from a network entity, a first message indicating a configuration for reporting spatial domain basis function updates to the network entity. The UE may transmit a full channel state information (CSI) report and a partial CSI report to the network entity based on the indicated configuration. The complete CSI report may indicate a set of spatial domain basis functions, and the partial CSI report may indicate an update to the set of spatial domain basis functions. The update to the set of spatial domain basis functions may be relative to the complete CSI report or a previously transmitted partial CSI report. In some examples, the UE may receive a second message from the network entity based on the partial CSI report.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. patent application No. 17 / 945,649, entitled “TECHNIQUES FOR SPATIAL DOMAIN BASIS FUNCTION REFINEMENT,” filed by VENUGOPAL et al. on September 15, 2022, which is assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates, for example, to wireless communication systems, including techniques for spatial domain basis function refinement. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

[0005] A wireless multiple access communication system may include one or more base stations, each of which supports wireless communications for communication devices, which may be referred to as user equipment (UE). In some wireless communication systems, the UE may perform channel estimation and report parameters associated with the estimated channel to a network entity. The network entity may use the reported parameters to increase the capacity of the channel through adaptive techniques such as channel precoding, interference suppression, and signal rank determination. In some cases, existing techniques for reporting parameters associated with the estimated channel may be deficient. Summary of the invention

[0006] The described technology relates to improved devices and apparatuses that support technology for spatial domain basis function refinement. For example, the described technology provides a framework for updating spatial domain basis functions used for channel precoding at a network entity. In some examples, a user equipment (UE) may receive a first message from a network entity indicating a configuration for reporting spatial domain basis function updates to the network entity. The UE may send a complete channel state information (CSI) report and a partial CSI report to the network entity based on the indicated configuration. The complete CSI report may indicate a set of spatial domain basis functions, and the partial CSI report may indicate an update to the set of spatial domain basis functions. In some examples, the update to the set of spatial domain basis functions may be relative to the complete CSI report or a previously sent partial CSI report. In some examples, the UE may receive a second message from the network entity based on the partial CSI report.

[0007] A method for wireless communication at a UE is described. The method may include receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity; sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and receiving a second message from the network entity based on the partial CSI report.

[0008] An apparatus for wireless communication at a UE is described. The apparatus may include: a processor; a memory coupled to the processor; and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a first message indicating a configuration for reporting a spatial domain basis function update to the network entity from a network entity; send a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and receive a second message from the network entity based on the partial CSI report.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity; means for sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and means for receiving a second message from the network entity based on the partial CSI report.

[0010] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions that can be executed by a processor to: receive a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity; send a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and receive a second message from the network entity based on the partial CSI report.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a third message from a network entity indicating that the UE reports an update to a set of spatial domain basis functions, wherein sending the partial CSI report may be based on the received third message.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a first message may include operations, features, components, or instructions for receiving an indication of an update to a set of reporting spatial domain basis functions relative to a complete CSI report or a previous partial CSI report, wherein sending a partial CSI report indicating an update may be based on the received indication.

[0013] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: sending a third message to the network entity requesting a report of an update to the set of spatial domain basis functions, wherein sending the partial CSI report may be based on the sent third message.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a partial CSI report may include operations, features, components, or instructions for sending an indication of a set of offsets to be applied to a set of spatial-domain basis functions, wherein each offset in the set of offsets corresponds to a respective spatial-domain basis function in the set of spatial-domain basis functions, and wherein the set of offsets indicates an update to the set of spatial-domain basis functions.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with a corresponding spatial-domain basis function and a second value corresponding to a zenith angle associated with the corresponding spatial-domain basis function.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a partial CSI report may include operations, features, components, or instructions for sending an indication of a shift in the positioning of a set of coefficients associated with a set of spatial-domain basis functions, wherein the shift in the positioning of the set of coefficients indicates an update to the set of spatial-domain basis functions.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the set of coefficients may have non-zero values.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an indication of a positioned shift of a set of coefficients may include operations, features, components, or instructions for sending a set of bits indicating a value of an index corresponding to a positioned shift of a set of coefficients.

[0019] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an indication of a shift in the positioning of a set of coefficients may include operations, features, components, or instructions for sending an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient differences indicate a shift in the value and the positioning of the corresponding coefficient in the set of coefficients.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a full CSI report and a partial CSI report may include operations, features, components, or instructions for sending a full CSI report at a first time instance and sending a partial CSI report at a second time instance after the first time instance, wherein the second time instance may be based on a prediction performed at the UE.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the prediction may be based on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a partial CSI report may include operations, features, components, or instructions for: receiving a third message indicating a set of multiple coefficient sets from a network entity, wherein each coefficient set in the indicated set of multiple coefficient sets corresponds to a corresponding set of spatial domain basis functions; and sending an indication of one or more coefficient sets in the indicated set of multiple coefficient sets to the network entity based on the received third message, wherein the one or more coefficient sets indicate an update to the set of spatial domain basis functions.

[0023] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an indication of one or more sets of coefficients may include operations, features, components, or instructions for sending an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients indicates a coefficient difference between a coefficient in a first set of coefficients in the indicated set of multiple sets of coefficients and a corresponding coefficient in a second set of coefficients in the indicated set of multiple sets of coefficients.

[0024] A method for wireless communication at a network entity is described. The method may include outputting a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and outputting a second message based on the partial CSI report.

[0025] An apparatus for wireless communication at a network entity is described. The apparatus may include: a processor; a memory coupled to the processor; and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to output a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; obtain a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and output a second message based on the partial CSI report.

[0026] Another apparatus for wireless communication at a network entity is described. The apparatus may include means for outputting a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; means for obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and means for outputting a second message based on the partial CSI report.

[0027] A non-transitory computer-readable medium storing code for wireless communication at a network entity is described. The code may include instructions executable by a processor to: output a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; obtain a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report; and output a second message based on the partial CSI report.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for outputting a third message instructing the UE to report an update to the set of spatial domain basis functions, wherein obtaining the partial CSI report may be based on outputting the third message.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, outputting a first message may include operations, features, components, or instructions for the following actions: outputting an indication of an update to a set of UE reporting spatial domain basis functions relative to a complete CSI report or a previous partial CSI report, wherein obtaining a partial CSI report indicating an update may be based on outputting the indication.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: obtaining a third message from the UE including a request to report an update to the set of spatial domain basis functions, wherein obtaining the partial CSI report may be based on outputting the third message.

[0031] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining a partial CSI report may include operations, features, components, or instructions for obtaining an indication of a set of offsets to be applied to a set of spatial-domain basis functions, wherein each offset in the set of offsets corresponds to a respective spatial-domain basis function in the set of spatial-domain basis functions, and wherein the set of offsets indicates an update to the set of spatial-domain basis functions.

[0032] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with a corresponding spatial-domain basis function and a second value corresponding to a zenith angle associated with the corresponding spatial-domain basis function.

[0033] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining a partial CSI report may include operations, features, components, or instructions for obtaining an indication of a shift in the positioning of a set of coefficients associated with a set of spatial-domain basis functions, wherein the shift in the positioning of the set of coefficients indicates an update to the set of spatial-domain basis functions.

[0034] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the set of coefficients may have non-zero values.

[0035] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining an indication of a positioned shift of a set of coefficients may include operations, features, components, or instructions for obtaining a set of bits indicating a value of an index corresponding to a positioned shift of a set of coefficients.

[0036] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining an indication of a shift in the positioning of a set of coefficients may include operations, features, components, or instructions for obtaining an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient differences indicate a shift in the value and the positioning of the corresponding coefficient in the set of coefficients.

[0037] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining a full CSI report and a partial CSI report may include operations, features, components, or instructions for obtaining a full CSI report at a first time instance and obtaining a partial CSI report at a second time instance after the first time instance, wherein the second time instance may be based on the first time instance and a prediction performed at the UE.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the prediction may be based on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining a partial CSI report may include operations, features, components, or instructions for: obtaining a third message indicating a set of multiple coefficient sets, wherein each coefficient set in the indicated set of multiple coefficient sets corresponds to a corresponding set of spatial-domain basis functions; and obtaining an indication of one or more coefficient sets in the indicated set of multiple coefficient sets based on outputting the third message, wherein the one or more coefficient sets indicate an update to the set of spatial-domain basis functions.

[0040] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, obtaining an indication of one or more sets of coefficients may include operations, features, components, or instructions for obtaining an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients indicates a coefficient difference between a coefficient in a first set of coefficients in the indicated set of multiple sets of coefficients and a corresponding coefficient in a second set of coefficients in the indicated set of multiple sets of coefficients. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 and Figure 2 Each illustrates an example of a wireless communication system supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure.

[0042] Figure 3 and Figure 4 Each illustrates an example of a process flow supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure.

[0043] Figure 5 and Figure 6 A block diagram of a device supporting techniques for spatial-domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0044] Figure 7 A block diagram of a communication manager supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0045] Figure 8 A diagram of a system including a device supporting techniques for spatial-domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0046] Fig. 9 and Fig.10 A block diagram of a device supporting techniques for spatial-domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0047] Fig.11 A block diagram of a communication manager supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0048] Fig.12 A diagram of a system including a device supporting techniques for spatial-domain basis function refinement in accordance with various aspects of the present disclosure is shown.

[0049] Figures 13 to 16 A flow chart illustrating a method supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0050] A wireless multiple access communication system may include one or more network entities, each network entity supporting communication of multiple communication devices at the same time, which may also be referred to as user equipment (UE). In some examples, such communication may be performed via beamforming using multiple antennas at a transmitting device (e.g., one of the network entity and the UE) and multiple antennas at a receiving device (e.g., the other of the network entity and the UE). In some examples, the UE and the network entity may share information about the quality of a communication channel (e.g., for transmitting communication) to improve signal reliability and communication efficiency. For example, a communication system may support a format for reporting channel state feedback, wherein the UE may perform channel estimation and report one or more parameters associated with the estimated channel to the network entity. In some examples, the reported parameters may be referred to as channel state information (CSI) and may include a layer indicator (LI), a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI), etc. In such examples, precoding performed at a network entity (e.g., to send a signal to a UE) may be determined at the network entity based on the CSI measured at the UE and reported to the network entity. That is, the network entity may determine a precoding matrix for precoding based on the CSI reported from the UE to the network entity.

[0051] However, in some examples, the UE may be traveling at a relatively high speed, such that the radio conditions (e.g., channel conditions) experienced at the UE may change relatively quickly compared to the rate at which the network entity can obtain CSI from the UE. Therefore, the precoding matrix determined at the network entity may become outdated relatively quickly and reduce the performance of communication (e.g., downlink communication) between the UE and the network entity. In order to improve communication performance (e.g., while reducing overhead), the UE may send a complete CSI report and one or more partial CSI reports to the network entity. The complete CSI report may include a set of spatial domain basis functions and a set of channel coefficients associated with the set of spatial domain basis functions. Additionally or alternatively, the partial CSI report may indicate changes in the set of channel coefficients. However, in some examples, the changes in the set of channel coefficients may fail to capture changes (e.g., decorrelation) in the spatial domain basis functions (e.g., changes over time due to changes in channel conditions), which may result in an outdated precoding matrix and reduced performance of downlink communication between the network entity and the UE.

[0052] Various aspects of the present disclosure relate to techniques for spatial domain basis function refinement, and more specifically to a framework for updating spatial domain basis functions used at a network entity. For example, a network entity may indicate to a UE a configuration for reporting spatial domain basis function updates to the network entity. In some examples, based on the indicated configuration, the UE may send a full CSI report and one or more partial CSI reports to the network entity. In such examples, the full CSI report may indicate a set of spatial domain basis functions. Additionally or alternatively, the full CSI report may indicate a set of coefficients (e.g., channel coefficients) associated with the set of spatial domain basis functions. In some examples, the partial CSI report may indicate an update to the set of spatial domain basis functions. For example, the partial CSI report may indicate an update to the set of spatial domain basis functions relative to a full CSI report (e.g., relative to a set of spatial domain basis functions indicated using a full CSI report) or relative to a previously sent partial CSI report (e.g., relative to a previously indicated update to a set of spatial domain basis functions indicated using a full CSI report).

[0053] In some examples, the UE may indicate an update to the spatial domain basis functions via one or more offsets to be applied to the spatial domain basis functions. For example, the UE may indicate to the network entity the offsets to be applied to each spatial domain basis function in the set of spatial domain basis functions. Additionally or alternatively, the UE may indicate an update via a shift in the positioning of one or more channel coefficients. For example, the UE may indicate to the network entity a shift in the positioning of a non-zero coefficient (e.g., one or more channel coefficients included in a set of channel coefficients having non-zero values). In such an example, the network entity may determine an update to the spatial domain basis functions based on the indicated shift in the positioning of the non-zero coefficients.

[0054] Various aspects of the subject matter described herein may be implemented to achieve one or more of the following potential advantages. For example, the techniques employed by the communication device may provide benefits and enhancements to wireless communication devices operating within a network, including improving the reliability of channel state feedback reports within a wireless communication system. In some examples, operations performed by the described communication device to improve the reliability of channel state feedback reports may include configuring the UE to update the spatial domain basis functions used at a network entity (e.g., for communication with the UE). In some other specific implementations, the operations performed by the wireless communication device may also support improvements to user experience and higher data rates, as well as other benefits. Various aspects of the present disclosure are first described in the context of wireless communication systems and process flows. Various aspects of the present disclosure are further illustrated and described by and with reference to device diagrams, system diagrams, and flow charts related to techniques for spatial domain basis function refinement.

[0055] Figure 1An example of a wireless communication system 100 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is illustrated. The wireless communication system 100 may include a network entity 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating according to other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0056] The network entities 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may include devices in different forms or with different capabilities. In various examples, the network entities 105 may be referred to as network elements, mobility elements, radio access network (RAN) nodes, or network equipment, among other nomenclatures. In some examples, the network entities 105 and the UE 115 may communicate wirelessly via one or more communication links (e.g., radio frequency access links) in the communication links 125. For example, the network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) within which the UE 115 and the network entity 105 may establish one or more communication links in the communication links 125. The coverage area 110 may be an example of a geographic area within which the network entity 105 and the UE 115 may support signal communications according to one or more radio access technologies (RATs).

[0057] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be devices in different forms or with different capabilities. Figure 1 Some examples of UE 115 are illustrated in FIG. UE 115 described herein may be capable of supporting communication with various types of devices (such as Figure 1 The UE 115 shown communicates with other UEs or network entities 105).

[0058] As described herein, a node of the wireless communication system 100 (which may be referred to as a network node or a wireless node) may be a network entity 105 (e.g., any network entity described herein), a UE 115 (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, the node may be a UE 115. As another example, the node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different relative to these examples. Similarly, references to UE 115, network entity 105, apparatus, device, computing system, etc. may include disclosure of UE 115, network entity 105, apparatus, device, computing system, etc. as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that the first node is configured to receive information from a second node.

[0059] In some examples, the network entities 105 may communicate with the core network 130, or with each other, or both. For example, the network entities 105 may communicate with the core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, the network entities 105 may communicate with each other via the backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols) directly (e.g., directly between the network entities 105) or indirectly (e.g., via the core network 130). In some examples, the network entities 105 may communicate with each other via the midhaul communication links 162 (e.g., according to the midhaul interface protocol) or the fronthaul communication links 168 (e.g., according to the fronthaul interface protocol) or any combination thereof. The backhaul communication links 120, the midhaul communication links 162, or the fronthaul communication links 168 may be or include one or more wired links (e.g., electrical links, optical fiber links), one or more wireless links (e.g., radio links, wireless optical links), etc. or various combinations thereof. UE 115 may communicate with core network 130 via communication link 155 .

[0060] One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a transceiver base station, a radio base station, an NR base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next-generation Node B, or a gigabit Node B (any of which may be referred to as a gNB), a 5G NB, a next-generation eNB (ng-eNB), a home Node B, a home evolved Node B, or other suitable terms). In some examples, the network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within the network entity 105 (e.g., a single RAN node such as the base station 140).

[0061] In some examples, the network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) that may be configured to utilize protocol stacks between two or more network entities (e.g., an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN))) that are physically or logically distributed in the network entity 105. For example, the network entity 105 may include one or more of the following: a central unit (CU) such as CU 160, a distributed unit (DU) such as DU 165, a radio unit (RU) such as RU 170, a RAN intelligent controller (RIC) such as RIC 175 (e.g., a near real-time RIC (near RT RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) such as SMO 180 system, or any combination thereof. The RU 170 may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmit receive point (TRP). One or more components of the network entity 105 in the decomposed RAN architecture may be co-located, or one or more components of the network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more of the network entities 105 of the decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0062] The functional split between CU 160, DU 165, and RU 170 is flexible and can support different functionalities, depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a functional split of a protocol stack can be employed between CU 160 and DU 165, such that CU 160 can support one or more layers of a protocol stack and DU 165 can support one or more different layers of a protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., layer 3 (L3), layer 2 (L2)) functionality and signaling (e.g., radio resource control (RRC), service data adaptation protocol (SDAP), packet data convergence protocol (PDCP)). The CU 160 may be connected to one or more of the DU 165 or RU 170, which may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally or alternatively, a functional split of the protocol stack may be employed between the DU 165 and the RU 170, such that the DU 165 may support one or more layers of the protocol stack, and the RU 170 may support one or more different layers of the protocol stack. The DU 165 may support one or more different cells (e.g., via one or more RUs 170). In some cases, the functional split between CU 160 and DU 165 or between DU 165 and RU 170 can be within the protocol layer (e.g., some functions of the protocol layer can be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer are performed by different ones of CU 160, DU 165, or RU 170). CU 160 can be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. CU 160 can be connected to one or more DUs in DU 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and DU 165 can be connected to one or more RU 170 via fronthaul communication links 168 (e.g., open fronthaul (FH) interface). In some examples, midhaul communication link 162 or fronthaul communication link 168 may be implemented based on interfaces (e.g., channels) between layers of a protocol stack supported by corresponding ones of network entities 105 that communicate via these communication links.

[0063] In some wireless communication systems (e.g., wireless communication system 100), infrastructure and spectrum resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities (e.g., IAB nodes 104) in network entity 105 may be partially controlled by each other. One or more IAB nodes in IAB node 104 may be referred to as a donor entity or an IAB donor. One or more DUs or one or more RUs 170 in DU 165 may be partially controlled by one or more CUs in CU 160 associated with a donor network entity (e.g., network entity 105, base station 140). One or more donor network entities (e.g., one or more network entities in network entity 105, one or more IAB donors) may communicate with one or more additional network entities (e.g., IAB nodes 104) in network entity 105 via supported access and backhaul links (e.g., backhaul communication links 120). The IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by a coupled IAB donor's DU 165. The IAB-MT may include an independent set of antennas for relaying communications with the UE 115, or may share the same antennas (e.g., of the RU 170) of the IAB node 104 for access via the DU 165 of the IAB node 104 (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, the IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes in the IAB node 104 or components of the IAB node 104) may be configured to operate according to the techniques described herein.

[0064] Where the techniques described herein are applied to the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture may be configured to support the techniques for spatial domain basis function refinement as described herein. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., an IAB node 104, a DU 165, a CU 160, a RU 170, a RIC 175, a SMO 180).

[0065] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or may be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0066] The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs in the UE 115, which may sometimes act as a relay, as well as network entities 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 shown.

[0067] The UE 115 and the network entity 105 may use resources associated with one or more carriers to wirelessly communicate with each other via one or more communication links (e.g., access links) in the communication link 125. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels of a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. According to the carrier aggregation configuration, the UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers. Communication between the network entity 105 and other devices may refer to communication between these devices and any part (e.g., entity, sub-entity) of the network entity 105. For example, the terms "send", "receive", or "communicate" when referring to the network entity 105 may refer to any part of the network entity 105 (e.g., base station 140, CU 160, DU 165, RU 170) of the RAN communicating with another device (e.g., directly or via another one or more network entities in the network entity 105).

[0068] The signal waveform transmitted via the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM technology, a resource element may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and the subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both), so that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high order modulation scheme may correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers, beams), and the use of multiple spatial resources may increase the data rate or data integrity of communications with UE 115.

[0069] The time interval for the network entity 105 or the UE 115 may be expressed in multiples of a basic time unit, which may be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the supported subcarrier spacing, and N f The supported discrete Fourier transform (DFT) size may be indicated. The time intervals of the communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0070] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a certain number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a certain number of symbol periods (e.g., depending on the length of the cyclic prefix appended in front of each symbol period). In some examples of the wireless communication system 100, the time slot may be further divided into micro-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating RF spectrum band.

[0071] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmit time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0072] Carrier multiplexing physical channels may be used for communication according to various techniques. Physical control channels and physical data channels may be multiplexed, for example, using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique to signal via a downlink carrier. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a set of symbol periods and may extend across a system bandwidth of a carrier or a subset of that system bandwidth. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more UEs in UE 115 may monitor or search a control region to obtain control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to a plurality of UEs among UEs 115 and a UE-specific search space set for transmitting control information to UE 115 .

[0073] In some examples, the network entities 105 (e.g., base stations 140, RUs 170) may be mobile and thus provide communication coverage for mobile coverage areas (e.g., coverage areas 110). In some examples, while different coverage areas associated with different technologies (e.g., different instances of coverage area 110) may overlap, the different coverage areas may be supported by network entities 105 (e.g., the same network entity). In some other examples, overlapping coverage areas associated with different technologies may be supported by different ones of the network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 use the same or different radio access technologies to provide coverage for various coverage areas (e.g., various instances of coverage area 110).

[0074] The wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private communication or group communication, and may be supported by one or more services (such as push-to-talk, video, or data). Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein.

[0075] In some examples, the UE 115 may be configured to support direct communication with one or more other UEs in the UE 115 via a device-to-device (D2D) communication link 135 (e.g., according to a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs in the group of UEs 115 that are performing D2D communication may be within a coverage area 110 of a network entity 105 (e.g., base station 140, RU 170), which may support aspects of such D2D communication configured (e.g., scheduled) by the network entity 105. In some examples, one or more UEs in such a group of UEs 115 may be outside of the coverage area 110 of the network entity 105, or may otherwise be unable or not configured to receive transmissions from the network entity 105. In some examples, the group of UEs 115 communicating via D2D communication may support a one-to-many (1:M) system, in which each UE 115 transmits to each of the other UEs in the group of UEs 115. In some examples, network entity 105 may facilitate scheduling of resources for D2D communications. In some other examples, D2D communications may be performed between UEs 115 without involving network entity 105.

[0076] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management of UE 115 served by a network entity 105 (e.g., a base station 140) associated with the core network 130. User IP packets may be transferred via the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the IP service 150 of one or more network operators. IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0077] The wireless communication system 100 may operate using one or more radio frequency spectrum bands that may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). The region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is approximately 1 decimeter to 1 meter. UHF waves may be blocked or redirected by buildings and environmental features (which may be referred to as clusters), but these waves may be sufficient to penetrate structures so that macro cells provide service to UEs 115 located indoors. Communications using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to communications using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0078] The wireless communication system 100 may utilize both licensed radio frequency spectrum bands and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), unlicensed radio frequency spectrum band radio access technology, or NR technology using unlicensed radio frequency spectrum bands (such as the 5 GHz industrial, scientific, and medical (ISM) band). When operating using an unlicensed radio frequency spectrum band, devices such as network entities 105 and UEs 115 may employ carrier sensing for conflict detection and avoidance. In some examples, operations using unlicensed radio frequency spectrum bands may be based on a carrier aggregation configuration combined with component carriers operating using a licensed radio frequency spectrum band (e.g., LAA). Operations using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, and the like.

[0079] The network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the network entity 105 or UE 115 may be located in one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with the network entity 105 may be located at different geographical locations. The network entity 105 may include an antenna array having a set of antenna ports of multiple rows and columns that the network entity 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals sent via the antenna ports.

[0080] The network entity 105 or UE 115 may use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by sending or receiving multiple signals via different spatial layers. Such a technology may be referred to as spatial multiplexing. Multiple signals may be, for example, sent by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technologies include single-user MIMO (SU-MIMO), for which multiple spatial layers are sent to the same receiving device; and multi-user MIMO (MU-MIMO), for which multiple spatial layers are sent to multiple devices.

[0081] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or direct an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals conveyed via antenna elements of an antenna array so that some signals propagating in some directions relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals conveyed via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with an orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0082] The network entity 105 or UE 115 may use beam scanning techniques as part of a beamforming operation. For example, the network entity 105 (e.g., base station 140, RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be sent multiple times by the network entity 105 along different directions. For example, the network entity 105 may send signals according to different sets of beamforming weights associated with different transmission directions. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device (such as network entity 105), or by a receiving device (such as UE 115)) beam directions for later transmission or reception by the network entity 105.

[0083] Some signals (such as data signals associated with a receiving device) may be sent by a transmitting device (e.g., network entity 105, UE 115) along a single beam direction (e.g., a direction associated with a receiving device such as network entity 105 or UE 115). In some examples, a beam direction associated with transmission along a single beam direction may be determined based on signals sent along one or more beam directions. For example, UE 115 may receive one or more of the signals sent by network entity 105 along different directions and may report to network entity 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0084] In some examples, transmission by a device (e.g., by network entity 105 or UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from network entity 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured set of beams across a system bandwidth or one or more subbands. Network entity 105 may send reference signals (e.g., cell-specific reference signals (CRS), CSI reference signals (CSI-RS)), which may be precoded or not precoded. UE 115 may provide feedback for beam selection, which may be PMI or codebook-based feedback (e.g., multi-panel codebook, linear combination codebook, port selection codebook). Although these techniques are described with reference to signals sent along one or more directions by a network entity 105 (e.g., base station 140, RU 170), UE 115 may use similar techniques to send signals multiple times along different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115), or to send signals along a single direction (e.g., to send data to a receiving device).

[0085] A receiving device (e.g., UE 115) may perform receiving operations according to multiple receiving configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a receiving device (e.g., network entity 105). For example, the receiving device may perform reception according to multiple receiving directions by: receiving via different antenna subarrays, processing the received signals according to different antenna subarrays, receiving according to different receiving beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or processing the received signals according to different receiving beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receiving configurations or receiving directions. In some examples, the receiving device may use a single receiving configuration to receive along a single beam direction (e.g., when receiving a data signal). A single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0086] In some examples, UE 115 may be traveling at a relatively high speed such that radio conditions experienced at UE 115 may change relatively quickly compared to the rate at which network entity 105 may obtain CSI from UE 115. Therefore, UE 115 may send a complete CSI report and one or more partial CSI reports to network entity 105. The complete CSI report may include a set of spatial domain basis functions and a set of coefficients (e.g., channel coefficients) associated with the set of spatial domain basis functions. Additionally or alternatively, the partial CSI report may indicate changes in the set of channel coefficients included in the complete CSI report. However, in some examples, changes in the set of channel coefficients may fail to capture changes in the spatial domain basis functions (e.g., decorrelation), which may result in an outdated precoding matrix and may degrade the performance of downlink communications between network entity 105 and UE 115.

[0087] In some examples, the wireless communication system 100 may support one or more techniques for spatial domain basis function refinement. For example, the network entity 105 may indicate to the UE 115 a configuration for reporting spatial domain basis function updates to the network entity 105. In some examples, based on the configuration, the UE 115 may send a complete CSI report and one or more partial CSI reports to the network entity 105. In such examples, the complete CSI report may indicate a set of spatial domain basis functions. Additionally or alternatively, the complete CSI report may indicate a set of channel coefficients associated with the set of spatial domain basis functions. In some examples, the partial CSI report may indicate an update to the set of spatial domain basis functions. For example, the partial CSI report may indicate an update of the set of spatial domain basis functions relative to the complete CSI report or relative to another (e.g., previously sent) partial CSI report. The UE 115 may receive a message from the network entity 105 based on the partial CSI report. In some examples, configuring the UE 115 to update the set of spatial domain basis functions may improve the reliability of communication between the UE 115 and the network entity 105, as well as other possible benefits.

[0088] Figure 2 An example of a wireless communication system 200 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 may implement or be implemented by one or more aspects of the wireless communication system 100. For example, the wireless communication system 200 may include a UE 215, which may be as described in reference Figure 1 The wireless communication system 200 may further include a network entity 205, which may be a network entity such as the one described in reference Figure 1Examples of one or more network entities (e.g., CU, DU, RU, base station, IAB node, or one or more other network nodes) in the network entity 105 are described. The network entity 205 and the UE 215 can communicate using the communication link 220, which can each be as described in reference Figure 1 An example of the communication link 125 is shown. The wireless communication system 200 may include features for improving communication between the network entity 205 and the UE 215, among other possible benefits.

[0089] The wireless communication system 200 may support MIMO communication to enable increased throughput within the wireless communication system 200. In some examples, to improve signal reliability and efficiency of MIMO communication, the network entity 205 and the UE 215 may share (e.g., exchange) information about the quality of the communication channel of the MIMO communication. For example, the UE 215 and the network entity 205 may support a framework for reporting channel state feedback, wherein the UE 215 may perform channel estimation (e.g., for the communication channel) and report CSI associated with the estimated communication channel to the network entity 205. In some examples, precoding performed by the network entity 205 (e.g., to send a signal to the UE 215) may be determined by the network entity 205 based on the reported CSI. For example, in response to receiving the CSI from the UE 215, the network entity 205 may determine a precoder (e.g., a precoding matrix 230) to be used for precoding the signal to be sent to the UE 215. That is, the precoding matrix 230 (e.g., determined using the reported CSI) may be used to generate the beam 221 (e.g., associated with the index b2) for communicating with the UE 215. For example, as the UE 215 travels along the path 210, the channel conditions experienced at the UE 215 may change, and thus, the precoding matrix 230 used at the network entity 205 may be updated.

[0090] However, in some examples, UE 215 may be traveling at a relatively high speed (e.g., along path 210), such that channel conditions for UE 215 may change relatively quickly (e.g., due to propagation delays associated with signaling an indication of the CSI to network entity 205) compared to the rate at which network entity 205 can obtain CSI from UE 215. As a result, the precoding matrix 230 selected at network entity 205 (e.g., based on the reported CSI) may become outdated relatively quickly and degrade performance of communications between network entity 205 and UE 215.

[0091] In some examples, to increase the reliability of communications for relatively high (or relatively medium) UE speeds, the wireless communication system may support one or more techniques for refining a codebook (e.g., a type II codebook) that may be used for CSI reporting. For example, the codebook may be used (e.g., at the network entity 205 and the UE 215) to determine the size of a precoding matrix 230, which may be used at the network entity 205 for precoding transmissions, such as MIMO transmissions using one or more data streams (e.g., one or more layers (l)). In some examples, the size (e.g., dimension) of the precoding matrix 230 may depend on the number of antennas (e.g., transmit antennas at the network entity 205) and the number of precoding matrices configured at the network entity 205 (e.g., the number of PMIs). Additionally or alternatively, the number of layers (l) used at the network entity 205 (e.g., for downlink transmissions) may be configured at the UE 215 (e.g., via signaling from the network entity 205, such as RRC signaling). In some examples, the size of precoding matrix 230 may be determined according to the following Equation 1:

[0092] N t ×N3(1)

[0093] Where N t N may correspond to the number of antennas (e.g., active antenna ports at network entity 205), and N3 may correspond to the number of PMIs (e.g., the number of radio frequency spectrum bands on which network entity 205 may precode). In some examples, the number of PMIs may be determined (e.g., at network entity 205) based on the number of CQI subbands and the number of PMI subbands (e.g., per CQI subband). In some examples, the CQI subband (or PMI subband) may correspond to a portion of the bandwidth represented by the reported CQI (or PMI). In some examples, the number of CQI subbands and the number of PMI subbands may be configured at UE 215 (e.g., via signaling from network entity 205, such as RRC signaling).

[0094] In some examples, for the transmission layer (l), the precoding matrix 230 (eg, a compressed type II precoder (W (l) )) can exploit the sparsity of the spatial domain and the frequency domain. For example, the CSI formula for the type II codebook can be used to indicate the pre-decoding matrix 230 using the structure described according to equation 2:

[0095]

[0096] Where W (l) can represent the pre-decoding matrix 230, W1 can represent the spatial domain basis function 235, W 2,lThe channel coefficients 240 (eg, spatial frequency domain channel coefficients) may be represented, and The frequency domain basis function 245 may be represented. In some examples, the pre-coding matrix 230 (eg, using the matrix W (l) ) may include a certain number of rows (N) which may be described according to Equation 3 t ):

[0097] N t =2N1N2 (3)

[0098] Where N1 may represent the spatial domain, and N2 may represent the number of antenna ports at the network entity 205. Additionally or alternatively, the precoding matrix 230 may include a number of columns (N3) that may each represent a frequency domain compression unit (e.g., including a resource block or a reporting subband).

[0099] In some examples, the spatial domain basis functions 235 (e.g., a spatial domain precoder represented using the matrix W1) may include spatial domain basis functions that take into account (e.g., include, account for) the number of beams (L) (e.g., to be used at the network entity 205). That is, the matrix W1 may include a number of spatial domain basis functions that may be based on (e.g., correspond to) the number of beams (L) at the network entity 205. For example, the spatial domain basis functions 235 may include a number of columns (L) for each polarization group (e.g., approximately 2L beams). In such an example, the i-th column of the matrix W1 may correspond to the i-th beam (b i ). In some examples, the spatial domain basis functions 235 (e.g., matrix W1) may be common to multiple layers (l). That is, for some transmissions (e.g., multi-stream MIMO transmissions), the same set of spatial domain basis functions may be used for multiple (e.g., each) layer (l). In some examples, the spatial domain basis functions 235 (e.g., basis vectors in the spatial domain, discrete Fourier transform basis vectors) may be expressed according to the following equation 4:

[0100] N t ×2L(4)

[0101] Wherein L beams may be selected for each polarization group (e.g., at the network entity 205). Additionally or alternatively, the parameter L may be configured at the UE 215 (e.g., via signaling from the network entity 205, such as via RRC signaling). In some examples, the CSI reported from the UE 215 to the network entity 205 may be based on the parameter L (e.g., and one or more other parameters to be used for downlink transmissions, such as the number of CQI subbands, the number of PMI subbands, and the number of layers (l)).

[0102] In some examples, channel coefficients 240 (eg, using matrix W 2,l) may include linear combinations of coefficients (e.g., amplitude and in-phase coefficients), where (e.g., the matrix W 2,l Each element of ) may represent a coefficient of a tap of a beam. Additionally or alternatively, channel coefficients 240 (eg, matrix W 2,l ) may be layer specific. That is, for some transmissions (e.g., multi-stream MIMO transmissions), multiple (e.g., different) sets of channel coefficients 240 may be used for multiple (e.g., different) layers (l). In some examples, such as for the type II precoding matrix composition for layer (l), the matrix W 2,l A row of may correspond to a spatial beam, and in the matrix W1, (eg, the matrix W 2,l The entries of W can represent the coefficients of the taps of the spatial beam. 2,l The size of (e.g., channel coefficient 240) may be expressed according to the following equation 5:

[0103] 2L×M(5)

[0104] Where the parameter 2L may correspond to the number of spatial domain basis functions 235, and the parameter may correspond to the number of frequency domain basis functions 245. That is, the matrix W 2,l The columns of may correspond to the frequency domain basis functions 245, and the matrix W 2,l The rows of may correspond to the spatial domain basis functions 235 .

[0105] In some examples, the parameters may be configured at the network entity 205 and the UE 215 (e.g., RRC configuration). For example, the network entity may indicate the parameters to the UE 215 via RRC signaling. Additionally or alternatively, the parameters may be based on the RI (e.g., may vary according to the RI). Additionally or alternatively, the channel coefficients 240 (e.g., using the matrix W 2,l In other words, for a single layer, the UE 215 may report K0 non-zero coefficients 241, and across multiple (e.g., all) layers, the UE 215 may report 2K0 non-zero coefficients 241 (e.g., within the channel coefficients 240) to the network entity 205.

[0106] In some examples, the matrix W 2,l The entries in can correspond to the matrix For example, the frequency domain basis function 245 may include basis vectors for performing compression in the frequency domain (eg, basis vectors in the frequency domain, discrete Fourier transform basis vectors). That is, the matrix Each row of may correspond to a basis vector. Additionally or alternatively, (e.g., using the matrix The frequency domain basis functions 245 (represented by ) may be layer specific. That is, for some transmissions (e.g., multi-stream MIMO transmissions), multiple (e.g., different) sets of frequency domain basis functions 245 may be used for multiple (e.g., different) layers (l). In some examples, the size of the frequency domain basis functions 245 may be represented according to the following equation 6:

[0107] M×N3. (6)

[0108] In some examples, UE 215 may report updates to precoding matrix 230, for example, based on channel conditions experienced at UE 215. For example, UE 215 may use (e.g., based on) updates to channel coefficients 240 (e.g., for matrix W 2,l ) to report the update of the pre-decoding matrix 230. That is, for relatively high or relatively medium UE speeds, UE 215 may modify the matrix W 2,l And it can avoid modifying the matrix W1 and the matrix (e.g., in a codebook). That is, the UE 215 may modify the matrix W 2,l ) (e.g., based on channel conditions experienced at UE 215) and report the modified value to network entity 205 so that network entity 205 can update (e.g., adapt) precoding matrix 230. For example, at a first time instance (t0), UE 215 can report an update to precoding matrix 230 so that precoding matrix 230 can be described according to the following equation 7:

[0109]

[0110] At a second time instance (t1) (eg, after the first time instance), the UE 215 may report an update to the precoding matrix 230 such that the precoding matrix 230 may be described according to the following Equation 8:

[0111]

[0112] And, at a third time instance (t2) (eg, after the first time instance and the second time instance), the UE 215 may report an update to the precoding matrix 230 such that the precoding matrix 230 may be described according to the following Equation 9:

[0113]

[0114] In some examples, W is reported at multiple (eg, different) time instances. 2,lThe values ​​of the matrix (e.g., channel coefficients 240) may enable the network entity 205 to track modifications to the precoding matrix 230 so that the precoding matrix 230 determined at the network entity 205 may be adapted to the channel conditions experienced at the UE 215. In such an example, the UE 215 may report the same values ​​for the spatial domain basis functions 235 (e.g., represented as the matrix W1) and for the frequency domain basis functions 245 (e.g., represented as the matrix W2). ) regardless of the time instance at which they are reported. That is, the spatial domain basis function 235 and the frequency domain basis function 245 may be static over a duration including the first time instance, the second time instance, and the third time instance.

[0115] In some examples, UE 215 uses the channel coefficient differences (e.g., relative to previously reported values ​​of channel coefficients 240) at multiple time instances to update precoding matrix 230. That is, UE 215 may report a set of channel coefficients 240 (e.g., matrix W) at multiple time instances. 2,l ) or a set of channel coefficients 240 (eg, matrix ΔW 2,l ). In some examples, if UE 215 reports a set of channel coefficients 240 (e.g., matrix ΔW) at multiple time instances 2,l ) changes, the matrix ΔW 2,l The elements included in may correspond to differential channel coefficients (eg, incremental reporting, partial CSI updates). For example, the elements included in the matrix ΔW 2,l The differential channel coefficients in can correspond to the difference with respect to W 2,l The channel coefficient differences of the corresponding channel coefficients of the matrix.

[0116] Additionally or alternatively, the channel coefficients 240 (or precoding matrix 230) may be determined (e.g., expressed) according to the time domain or the Doppler domain (e.g., Doppler frequency). In such examples, the UE 215 may report the precoding matrix 230 (e.g., using the PMI) such that the precoding matrix 230 may include the matrix W 2,l, a time domain representation of the channel coefficients 240. Thus, the network entity 205 may determine modifications to the precoding matrix 230 for a duration (e.g., may adapt the precoding matrix). In some other examples, the precoding matrix 230 may be determined (e.g., expressed, described) according to a state-space representation in which the precoding matrix 230 may be updated for a duration using a recursive equation. For example, the UE 215 may report feedback about the channel coefficients 240 to the network entity 205 (e.g., may send a CSI report), and based on a model (e.g., an alternative model, a state-space representation, a state-space model), the network entity 205 may determine (e.g., calculate) the precoding matrix 230. That is, the network entity 205 may track the CSI associated with the UE 215 based on the recursive equation, and may update the precoding matrix 230 based on the tracked CSI (e.g., one or more observations).

[0117] In some examples, changes in the set of channel coefficients (e.g., reported from the UE 215) may fail to capture changes (e.g., decorrelation) in the spatial domain basis functions 235 and may result in reduced performance of downlink communications between the network entity 205 and the UE 215. For example, (e.g., for frequency range 2 (FR2) and relatively higher radio frequency spectrum bands, such as radio frequency spectrum bands including millimeter wavelengths), the spatial domain basis functions 235 (e.g., selected at the UE 215) may become decorrelated over a certain duration due to changes in channel conditions. Therefore, the UE 215 may adapt the spatial domain basis functions 235 over a certain duration based on the channel conditions (e.g., based on the Doppler frequency). For example, to increase the reliability of the precoding matrix 230, the UE 215 may report modifications to the spatial domain basis functions 235 (e.g., in addition to modifications to the channel coefficients 240) based on the channel conditions experienced at the UE 215.

[0118] In some examples, as described herein, techniques for spatial domain basis function refinement can provide one or more enhancements to CSI reporting in the wireless communication system 200 (e.g., evolved MIMO communications including one or more CSI enhancements can be provided). For example, such techniques can provide one or more CSI reporting enhancements for relatively high or relatively medium UE speeds by utilizing time domain correlation or Doppler domain information (or both), for example, to assist in precoding (e.g., downlink precoding or uplink precoding) for one or more frequency ranges (e.g., frequency range 1 (FR1), FR2). That is, the wireless communication system 200 can support an enhanced framework for CSI reporting, wherein the network entity 205 can use time domain related information or Doppler domain information (or both) to adapt the precoding matrix 230 used at the network entity 205 (e.g., for data transmission). In some examples, as described herein, techniques for spatial domain basis function refinement can provide one or more refinements of a codebook (e.g., a type II codebook) (e.g., without modifying the spatial domain basis functions and the frequency domain basis functions).

[0119] Additionally or alternatively, such techniques may enable the UE to report time domain channel properties measured, for example, via a reference signal (e.g., CSI-RS) for tracking. In some examples, techniques for spatial domain basis function refinement may use multiple TRPs (mTRPs) (such as up to 4 TRPs) to provide one or more enhancements to CSI acquisition for coherent joint transmission (CJT). Such techniques may be used with one or more frequency ranges (e.g., FR1, FR2). In some examples, such enhancements for CSI acquisition may include backhaul (e.g., ideal backhaul) communications and synchronization (e.g., between TRPs), and the same number of antenna ports across multiple TRPs. For example, type II codebook refinement for CJT using mTRPs (e.g., for frequency division duplexing (FDD)) and associated CSI reporting may take into account throughput-overhead tradeoffs.

[0120] like Figure 2As illustrated in the example of , the network entity 205 may send an indication of a configuration (e.g., CSI reporting configuration 225) for reporting spatial domain basis function updates to the network entity 205 to the UE 215. In some examples, based on the CSI reporting configuration 225, the UE 215 may send a full CSI report 250. The full CSI report 250 may indicate at least a set of spatial domain basis functions (e.g., spatial domain basis functions 235). For example, the full CSI report 250 may indicate the spatial domain basis functions 235 and the channel coefficients 240. Additionally or alternatively, the full CSI report 250 may indicate the frequency domain basis functions 245. In some examples, the UE 215 may send a partial CSI report 255. The partial CSI report 255 may indicate an update to the spatial domain basis functions 235. In some examples, the partial CSI report 255 may indicate an update of the spatial-domain basis functions 235 relative to the full CSI report 250 (e.g., relative to the spatial-domain basis functions 235 indicated using the full CSI report 250). Additionally or alternatively, the partial CSI report 255 may indicate an update of the set of spatial-domain basis functions 235 relative to a previously sent partial CSI report (e.g., relative to a previously sent update to the spatial-domain basis functions 235 indicated using the full CSI report 250). In some examples, the UE 215 may receive a message 260 from the network entity 205 based on the partial CSI report. Configuring the UE 215 to update the set of spatial-domain basis functions may improve reliability of communications between the UE 215 and the network entity 205, among other possible benefits.

[0121] Figure 3 An example of a process flow 300 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is illustrated. The process flow 300 may implement, at or using one or more aspects of the wireless communication system 100 and the wireless communication system 200. For example, the process flow 300 may be implemented at the network entity 305 and the UE 315, which may be reference Figure 1 and Figure 2 Examples of corresponding devices described herein. In some examples, the network entity 305 and the UE 315 may implement the process flow 300 to improve network efficiency by supporting a framework for updating the spatial domain basis function. The process flow 300 may also be implemented by the network entity 305 and the UE 315 to promote high reliability and low latency operation and other benefits. In the following description of the process flow 300, the operations between the UE 315 and the network entity 305 may be performed in an order different from the example order shown. Additionally or alternatively, the operations performed by the UE 315 and the network entity 305 may be performed in a different order or at different times. Some operations may also be omitted.

[0122] like Figure 3 As illustrated in the example of , the network entity 305 may configure the UE 315 to report updates to the set of spatial domain basis functions (e.g., based on channel conditions experienced at the UE 315). For example, at 320, the UE 315 may receive a message indicating a CSI reporting configuration. The CSI reporting configuration may be as described throughout this disclosure (including references to Figure 2 ) is an example of a CSI reporting configuration as described in the preceding claims. For example, the CSI reporting configuration may be used to report a spatial domain basis function update to the network entity 305. In some examples, the CSI reporting configuration may be a codebook configuration having a spatial domain basis function update feature. That is, the CSI reporting configuration may include an indication to enable partial CSI reporting at the UE 315. In some examples, the network entity 305 may indicate the CSI reporting configuration to the UE 315 using a higher layer parameter (e.g., such as via RRC signaling), such as via a higher layer parameter that may be used to indicate a codebook configuration, a measurement configuration (e.g., one or more resources to be used at the UE 315 to perform CSI measurements), or a reporting configuration (e.g., one or more time instances in which the UE 315 may perform CSI reporting), or any combination thereof.

[0123] At 330, UE 315 may send a complete CSI report indicating at least a set of spatial domain basis functions to network entity 305. The complete CSI report may be as described throughout this disclosure (including references to Figure 2 ) as described in the example of a complete CSI report. For example, the complete CSI report may be based on a CSI report configuration (e.g., indicated to the UE 315 at 320) and include a set of spatial domain basis functions (e.g., and a set of channel coefficients associated with the spatial domain basis functions). That is, the complete CSI report may include spatial domain basis function feedback (e.g., initial feedback for matrix W1, as shown in reference Figure 2 as described), for example, as part of a CSI report (eg, a Type II codebook CSI report).

[0124] In some examples, the full CSI report sent at 330 can be based on measurements performed at UE 315. For example, at 325, UE 315 can receive a first reference signal from network entity 305. The first reference signal can be an example of a CSI-RS or one or more other types of downlink reference signals. UE 315 can perform one or more measurements using the first reference signal and can use the one or more measurements to determine (e.g., select, identify) a set of spatial domain basis functions (e.g., and a set of channel coefficients) indicated using the full CSI report sent at 330.

[0125] At 345, UE 315 may send a partial CSI report indicating an update to the set of spatial domain basis functions to network entity 305. The partial CSI report may be as described throughout this disclosure (including references to Figure 2 ). For example, the partial CSI report may be based on a CSI report configuration and include updates to a set of spatial domain basis functions relative to a complete CSI report sent at 330 or relative to a previously sent partial CSI report (e.g., one or more updates to corresponding angles (θ) associated with one or more spatial domain basis functions, such as may be indicated using a change in angle with basis element {i} (e.g., represented using a parameter Δθ)). For example, the UE 315 and the network entity 305 may support an extension of the spatial domain basis functions such that the spatial domain basis functions may be time-varying (e.g., time-varying spatial domain basis functions may be supported). In some examples, the spatial domain basis functions may appear in two dimensions (2D) (e.g., in contrast to frequency domain basis functions and time domain or Doppler domain basis functions that may appear in one dimension (1D)). In such examples, the UE 215 may report time-varying spatial domain basis functions in three dimensions (3D) (e.g., an azimuth dimension, a zenith dimension, and a time dimension), which may result in increased overhead. However, in some examples, the spatial domain basis function (e.g., for a type II codebook) may be based on a discrete Fourier transform. Thus, the UE 315 may use a change in an angle associated with the spatial domain basis function (e.g., indicated using a value of a parameter Δθ) to indicate an update to the spatial domain basis function. For example, the spatial domain basis function (e.g., a discrete Fourier transform basis function) may be based on the following equation:

[0126] Formula 10 describes:

[0127]

[0128] where j can represent an imaginary number (e.g., ), k may represent a frequency, and N may represent an integer (e.g., the number of points, the number of samples). Thus, at a first time instance (e.g., at time t=0), the set of spatial domain basis functions may be represented as Additionally or alternatively, at a second time instance (eg, at time t), the set of spatial domain basis functions may be expressed as In some examples, the value of the parameter Δθ (e.g., for each spatial domain basis function) can be indicated (e.g., from UE 315) using multiple values ​​(e.g., a pair of values), such as a value for the azimuth dimension (e.g., the azimuth angle) and a value for the zenith dimension (e.g., the zenith angle).

[0129] In some examples, the UE 315 may indicate multiple values ​​of the parameter Δθ for the set of spatial domain basis functions (e.g., a different value of the parameter Δθ for each column of the matrix W1). For example, the UE 315 may indicate one or more Δθ values ​​to be applied for a full CSI report (e.g., each column of the matrix W1 indicated using the full CSI report) or another partial CSI report (e.g., each value of the parameter Δθ previously indicated using the other partial CSI report) for a certain duration (e.g., at the network entity 305). That is, the columns of the matrix W1 may correspond to discrete Fourier transform basis functions (e.g., oversampled discrete Fourier transform basis functions), and therefore, the UE 315 may use an offset value to indicate the parameter Δθ (e.g., may report the Δθ indication) so that the network entity 305 may determine an update to the set of spatial domain basis functions based on the offset value. For example, the UE 315 may use the offset value to indicate to the network entity 305 an updated spatial domain basis function (e.g., an updated beam index (b i )), the updated spatial domain basis function may have a value selected from (e.g., determined from, included in) a set of indices denoted as {0, 1, ..., O1N1-1} and {0, 1, ..., O2N2-1}, where N1 and N2 may correspond to antenna elements (e.g., antenna configuration values) at the network entity 305, and O1 and O2 may correspond to oversampling factors. In such an example, the set of indices, the antenna configuration values, and the oversampling factors may be included in the CSI configuration indicated to the UE 315 at 320. For example, at time t0 (e.g., using the full CSI report sent at 330), the UE 315 may indicate to the network entity 305 the spatial domain basis function (e.g., beam index (b i )). In such an example, based on the complete CSI report sent at 330, the network entity 305 may determine the spatial domain basis functions according to the following equations 11 and 12:

[0130]

[0131] in can correspond to the first dimension of the spatial domain basis function, t1 may correspond to the second dimension of the spatial domain basis function, and i may represent the index of the spatial domain basis function (e.g., the spatial domain basis vector, such that i=0, 1, ..., L-1). Additionally or alternatively, at time t1 (e.g., using the number of bits included in the partial CSI report sent at 345), the UE 315 may use an offset to indicate an update to the spatial domain basis function. For example, the UE 315 may indicate an update to the spatial domain basis function for The offset (for example, parameter ) and for The offset (for example, parameter In such an example, the network entity 305 may determine an updated spatial domain basis function (e.g., a beam formed using the updated spatial domain basis function) according to the following equations 13 and 14:

[0132]

[0133] In some examples, compared to sending a full CSI report (e.g., reporting the CSI for each beam (i) that can be used to derive and i 1,1 and i 1,2 ), using an offset value (e.g., parameter and ) to indicate the spatial domain basis function (for example, for each beam (b i )) may result in reduced overhead (e.g., may include using relatively fewer bits).

[0134] In some examples, the offset value can be based on measurements performed at UE 315. For example, at 335, UE 315 can receive a second reference signal from network entity 305. The second reference signal can be an example of a CSI-RS or one or more other types of downlink reference signals. UE 315 can perform one or more measurements using the second reference signal and can use the one or more measurements to determine (e.g., select, identify) an offset value indicated using the partial CSI report sent at 345.

[0135] In some examples, the UE 315 may send a partial CSI report based on an update indication received from the network entity 305 at 345. For example, at 340, the UE 315 may receive an update indication from the network entity 305. In some examples, the update indication received at the UE 315 at 340 may include a request for the UE 315 to send a partial CSI report at 345. Additionally or alternatively, the update indication received at the UE 315 at 340 may indicate a time instance (or multiple time instances, such as during a duration) during which the UE 315 may send a partial CSI report. Additionally or alternatively, the update indication received at the UE 315 at 340 may indicate the UE 315 to send a partial CSI report periodically, such as using periodic reporting. That is, in some examples, the network entity 305 may send an update indication at 340 to activate (or deactivate) partial CSI reporting at the UE 315. In some examples, UE 315 may request to send a partial CSI report at 345. For example, at 341, UE 315 may send an update request to network entity 305 to send a partial CSI report at 345 (eg, to update the spatial domain basis functions).

[0136] Figure 4 An example of a process flow 400 supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is illustrated. The process flow 400 may implement or may be implemented at or using one or more aspects of the wireless communication system 100, the wireless communication system 200, and the process flow 300. For example, the process flow 400 may be implemented at the network entity 405 and the UE 415, which may be reference Figures 1 to 3 Examples of corresponding devices described herein. In some examples, the network entity 405 and the UE 415 may implement the process flow 400 to improve network efficiency by supporting a framework for updating the spatial domain basis function. The process flow 400 may also be implemented by the network entity 405 and the UE 415 to promote high reliability and low latency operation and other benefits. In the following description of the process flow 400, the operations between the UE 415 and the network entity 405 may occur in an order different from the example order shown, or the operations performed by the UE 415 and the network entity 405 may be performed in a different order or at different times. Some operations may also be omitted.

[0137] like Figure 4 As illustrated in the example of , the network entity 405 may configure the UE 415 to report updates to the set of spatial domain basis functions (e.g., based on channel conditions experienced at the UE 415). For example, at 420, the UE 415 may receive a message indicating a CSI reporting configuration. The CSI reporting configuration may be as described throughout this disclosure (including references to Figure 2 and Figure 3 ) is an example of a CSI reporting configuration as described in . For example, the CSI reporting configuration may be used to report a spatial domain basis function update to the network entity 405. In some examples, the CSI reporting configuration may be a codebook configuration having a spatial domain basis function update feature.

[0138] At 430, UE 415 may send a complete CSI report indicating a set of spatial domain basis functions and a set of channel coefficients to network entity 405. A complete CSI report may be as described throughout this disclosure (including references to Figure 2 and Figure 3 ) is an example of a full CSI report as described in the foregoing. For example, the full CSI report may be based on the CSI reporting configuration indicated to the UE 415 at 420. Additionally or alternatively, the full CSI report sent at the UE 415 at 430 may be an example of a Type II codebook CSI report.

[0139] In some examples, the full CSI report sent at UE 415 at 430 can be based on measurements performed at UE 415. For example, at 425, UE 415 can receive a first reference signal from network entity 405. The first reference signal can be an example of a CSI-RS or one or more other types of reference signals (e.g., downlink reference signals). UE 415 can perform one or more measurements using the first reference signal, and can determine (e.g., select, identify) a set of spatial domain basis functions (e.g., and a set of channel coefficients) using the one or more measurements.

[0140] At 445, UE 415 may send a partial CSI report indicating values ​​of a set of coefficients (e.g., channel coefficients) and a positioned shift to network entity 405. For example (e.g., for relatively higher radio frequency spectrum band operations), according to one or more specific implementations, network entity 405 may generate one or more beams (e.g., an analog block may be used to perform a beamforming operation to generate a pattern of antenna elements to be used to send data to UE 415). That is, network entity 405 may include multiple antenna panels (e.g., multiple subarrays, multiple antenna assemblies), and may use an antenna panel (e.g., from a plurality of antenna panels) to generate a beam in a certain direction. In such an example, while network entity 405 may use a beam (e.g., generated using one or more antenna ports (such as two antenna ports)) for a certain duration (e.g., as an extension of type II codebook operation), network entity 405 may activate multiple beams (e.g., using multiple other antenna ports). Therefore, at a time instance (e.g., for some CSI feedback), matrix W 2,l The structure of may depend on the number of beams activated at the network entity 405. For example, the matrix W2,l The number of rows included in W1 may correspond to the number of beams (eg, columns of matrix W1) activated at network entity 405. In such an example, matrix W 2,l (eg, a set of channel coefficients) may include K0 non-zero coefficients per layer (l) (eg, 2K0 non-zero coefficients across multiple layers).

[0141] In some examples, K0 non-zero coefficients (eg, included in a set of channel coefficients associated with a spatial domain basis function) may be located along W 2,l The i-th and (i+L)-th rows in the matrix (for example, in the matrix W 2,l ) appears, where the i-th beam (b i ) can be used at the network entity 405 (e.g., for communication with the UE 415). In some examples, the i-th beam (b i ) may correspond to a CSI resource index (CRI) value (e.g., CRI-i). In such an example, parameter K0 may have a value at least equal to 2M (e.g., matrix W 2,l may include at least 2M non-zero coefficients), and (2L-2) rows may have zero values. Additionally or alternatively, in some examples, the i-th beam (b i ) may correspond to a combination of multiple beams. That is, multiple beams may be used (e.g., available for use) at the network entity 405. For example, the i-th row and the j-th row (e.g., and the corresponding cross-polarization ((i+L)-th and (j+L)-th) antenna ports) may be used at the network entity 405. That is, the network entity 405 may use a beam range from beam k to beam l. For example, the network entity 405 may use beams k, k+1, k+2, ... l. In such an example, the network entity 405 may indicate to the UE 415 the rows and columns used at the network entity 405.

[0142] In some examples, network entity 405 may determine that UE 415 may move in a certain direction. Therefore, network entity 405 may determine to adapt one or more beams (e.g., used at network entity 405 to communicate with UE 415) according to the direction in which UE 415 may move. That is, network entity 405 may increase or decrease the beam index (b) based on the direction in which UE 415 may move. i ). In some examples, to adapt the set of spatial domain basis functions, UE 415 may indicate (e.g., signal to network entity 405) the channel coefficient matrix (e.g., W 2,l matrix), where the non-zero coefficients (e.g., non-zero entries) can be relative to (e.g., the previously reported W 2,lThe positions of the non-zero coefficients in the previously reported set of channel coefficients of the matrix are shifted (e.g., row by row).

[0143] In some examples, the network entity 405 may group the beams (e.g., cluster the beams). For example, the columns of the W1 matrix may correspond to the active beams at the network entity 405, and the multiple active beams may be grouped such that W 2,l The shift in the rows of the matrix (e.g., a row-by-row shift of the non-zero coefficients) may result in a shift of the spatial domain basis functions used at the network entity 405 (e.g., a shift of the grouped beams). In such an example, the network entity 405 may have controllability to indicate to the UE 415 the type of row shift to be performed at the network entity 405 (e.g., to adapt the grouped beams, to adapt the spatial domain basis functions). For example, based on the indicated type of row shift, the UE 415 may indicate to the network entity 405 a row-by-row shift of the positioning of the non-zero coefficients (e.g., as an integer, such as ±{1, 2...}), such as using the number of bits included in the partial CSI report sent at the UE 415 at 445. That is, the UE 415 may use feedback associated with the channel coefficients (e.g., using ΔW 2,l feedback) to indicate the row-by-row shift.

[0144] In some examples, as part of a partial CSI report (e.g., as part of sending a partial CSI report at 445 to update the spatial domain basis functions), one or more bits (e.g., using a bit field (c i ) may be used to indicate (e.g., signal) the location of the non-zero coefficients (e.g., in W 2,l For example, the UE 415 may include bits "00" in the partial CSI report sent at 445 (or may avoid including one or more bits) to indicate to the network entity 405 that the same positioning of the non-zero coefficients is maintained (e.g., using the full CSI report sent at UE 415 at 430 to indicate to the network entity 405). 2,l matrix). That is, the UE 415 may include bits "00" to indicate to the network entity 405 that the same set of spatial domain basis functions is used (e.g., avoiding updating the spatial domain basis functions). For example, the UE 415 may include bits "00" in the partial CSI report (or may avoid including one or more bits) to indicate to the network entity 405 that the same set of beams is used as indicated using the previously reported CSI (e.g., using the full CSI report sent at the UE 415 at 430 or the previously sent partial CSI report).

[0145] In some examples, the non-zero coefficients are located (e.g., in the matrix W 2,lA shift of one row within) can be mapped to a bit field (c i ) code point. For example, bit "01" may indicate (e.g., in matrix W 2,l The code point value "01" may indicate to the network entity 405 that a neighboring beam that may follow (e.g., in the index) the value 1 is used. Additionally or alternatively, a bit "10" may indicate (e.g., in the matrix W) a shift of 1 row in the positioning of the non-zero coefficients within the space domain basis function and may thus indicate a shift of the space domain basis function by 1 index. That is, the bit "01" may indicate an increase in the index associated with the space domain basis function by the value 1. For example, the code point value "01" may indicate to the network entity 405 that a neighboring beam that may follow (e.g., in the index) the value 1 is used. Additionally or alternatively, a bit "10" may indicate (e.g., in the matrix W 2,l ) by a shift of -1 rows in the positioning of non-zero coefficients within, and thus may indicate a shift of the spatial domain basis functions by -1 indices. That is, bit "10" may indicate a decrease in the index associated with the spatial domain basis function by a value of 1. For example, a codepoint value of "10" may indicate to the network entity 405 to use a neighboring beam that may be (e.g., in the index) before the value 1. In some examples, bit "11" may indicate, for example, a reset of a partial CSI report using some reference CSI (e.g., a full CSI report). That is, the codepoint value "11" may indicate to the network entity 405 that the UE 415 sends a request to the network entity 405 for an indication of a set of spatial domain basis functions (e.g., using a full CSI report). It should be understood that the bits described herein may change based on the specific implementation of one or more devices (e.g., UE 415, network entity 405, or both), and the examples described herein should not be considered to be limited to the scope covered by the claims or the present disclosure.

[0146] In some examples, UE 415 may indicate a partial CSI report (e.g., an update to the spatial domain basis functions) with reference to a previous partial CSI report (e.g., a previous row-shifted set of channel coefficients) at 445. For example, the partial CSI report (e.g., including an update to the set of channel coefficients) sent at 445 may be based on (e.g., included in the matrix Some reference channel coefficient values ​​(eg, included in the matrix In this example,

[0147] In the reference channel coefficient value May include index positions for shifts (e.g., bit fields (c i )), for example, to indicate the change of the spatial domain basis function. For example, for a channel coefficient set (for example, represented as a matrix ) can be determined according to the following equation 15:

[0148]

[0149] Where n may correspond to an index associated with a time instance (e.g., a timestamp) at which an update may be reported (e.g., from UE 415 using a partial CSI report sent at 445). In such an example, a channel coefficient set (e.g., matrix ) can indicate the shift of the channel coefficient value and the shift of the channel coefficient location. That is, the matrix The value of the channel coefficient set can be indicated and the shift of the spatial domain basis functions (e.g., by using Additionally or alternatively, the partial CSI report sent at UE 415 at 445 may be indicated with reference to the full CSI report sent at 430. That is, the partial CSI report sent at 445 may indicate an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report.

[0150] In some examples, the update of the spatial domain basis function can be extended to report partial CSI based on prediction. For example, the update of the partial spatial domain basis function can be sent from the UE 415 based on the predicted timestamp. In some examples, the timestamp can be determined (e.g., at the UE 415) according to the following equation 16:

[0151] nR1+mR2 (16)

[0152] Wherein parameter R1 may correspond to a CSI measurement rate, parameter R2 may correspond to a CSI update rate (or a partial CSI reporting rate), and m may correspond to another index associated with another time instance (e.g., another timestamp) at which updates may be reported. Additionally or alternatively, the timestamp may be determined at UE 415 based on measurements performed at UE 415. For example, at 435, UE 415 may receive a second reference signal (e.g., a periodic CSI resource sent to UE 415 at 435) (e.g., such as from network entity 405 using a periodic CSI resource). In such an example, the time instance (e.g., time slot) at which UE 415 may send a partial CSI report may be based on measurements performed using the second reference signal or one or more predictions performed at UE 415 (e.g., or both). In some examples, the rate at which UE 415 may perform predictions may be different from another rate at which UE 415 may perform measurements (e.g., the CSI measurement rate indicates the use of parameter R1).

[0153] In some examples, movement of UE 415 may occur so that positioning of UE 415 may occur within an area (e.g., a geographic area) that can be served using a beam at network entity 405. That is, movement of UE 415 may be in the direction of a single beam at network entity 405. In some other examples, movement of UE 415 may occur so that positioning of UE 415 occurs outside an area (e.g., a geographic area) that can be served using a beam (or one or more other beams) at network entity 405. That is, UE 415 may be located between two areas served using two (e.g., different) beams at network entity 405. Additionally or alternatively, for relatively higher radio frequency spectrum bands, the spatial domain basis functions may be based on one or more specific implementations of network entity 405. That is, the spatial domain basis functions may include discrete Fourier transform basis functions or one or more other types (e.g., non-discrete Fourier transform) basis functions. In such examples, shifting of rows indicating channel coefficients may not be sufficient. Thus, the UE 415 (eg, and the network entity 405) may be configured to indicate a neighboring row (eg, a beam used at the network entity 405, such as a beam index (b i ) associated with the beam) adjacent to the row). For example, the UE 415 may indicate one or more rows, which may be represented as {i-1, i, i+1}. For example, at a first time instance, the i-th row may include non-zero coefficients. In such an example, at a subsequent time instance, the UE 415 may indicate one or more rows adjacent to the i-th row (e.g., row i and row i-1 or row i+1 may be indicated) to the network entity 405 so that the network entity 405 may combine multiple beams (e.g., a beam combination corresponding to a combination of row i and row i-1 or row i and row i+1 may be combined) to serve the area between the two beams (e.g., the area between row i and row i-1 or between row i and row i+1).

[0154] Additionally or alternatively, the network entity 405 may configure a set of candidate coefficients (e.g., candidate channel coefficients that may each be associated with an index) at the UE 415. For example, the network entity 405 may indicate one or more sets of channel coefficients to the UE 415, and each channel coefficient may correspond to a corresponding set of spatial domain basis functions (e.g., and each set of channel coefficients may correspond to a corresponding set of spatial domain basis functions). In such an example, the UE 415 may indicate a selection among the one or more sets of candidate coefficients configured at the UE 415. For example, the UE 415 may indicate an index corresponding to a set of candidate coefficients or a plurality of indices corresponding to a plurality of candidate coefficients (e.g., included in one or more sets of candidate coefficients configured at the UE 415). In some examples, the UE 415 may indicate an index of a set of candidate coefficients (or a plurality of indices corresponding to a plurality of candidate coefficients) with a row shift indication. For example, the UE 415 may send one or more indications of a set of candidate coefficients to the network entity 405, which may indicate an update to a set of spatial domain basis functions. That is, the network entity 405 may configure and activate a set of candidate beams from which the UE 415 may report changes in the spatial domain basis functions (e.g., via indicating a set or subset of candidate coefficients). Thus, the network entity 405 may generate a beam in the direction of the UE 415, thereby improving the performance of wireless communications between the UE 415 and the network entity 405, as well as other possible benefits.

[0155] In some examples, the UE 415 may send a partial CSI report based on an update indication received from the network entity 405 at 445. For example, at 440, the UE 415 may receive an update indication from the network entity 405. In some examples, the update indication received at the UE 415 at 440 may include a request for the UE 415 to send a partial CSI report at 445. Additionally or alternatively, the update indication received at the UE 415 at 440 may indicate a time instance (or multiple time instances, such as during a duration) during which the UE 415 may send a partial CSI report. Additionally or alternatively, the update indication received at the UE 415 at 440 may indicate the UE 415 to send a partial CSI report periodically, such as using periodic reporting. That is, in some examples, the network entity 405 may send an update indication at 440 to activate (or deactivate) partial CSI reporting at the UE 415. In some examples, activating (or deactivating) partial CSI reporting at UE 415 may increase the reliability of wireless communications between UE 415 and network entity 405, among other possible benefits.

[0156] Figure 5A block diagram 500 of a device 505 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 505 can be an example of various aspects of the UE 115 as described herein. The device 505 may include a receiver 510, a transmitter 515, and a communication manager 520. The device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0157] The receiver 510 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques for spatial domain basis function refinement). The information may be communicated to other components of the device 505. The receiver 510 may utilize a single antenna or a collection of multiple antennas.

[0158] The transmitter 515 may provide means for transmitting signals generated by other components of the device 505. For example, the transmitter 515 may transmit information associated with various information channels (e.g., control channels related to techniques for spatial domain basis function refinement, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 515 may be co-located with the receiver 510 in a transceiver component. The transmitter 515 may utilize a single antenna or a collection of multiple antennas.

[0159] The communication manager 520, the receiver 510, the transmitter 515, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of the techniques for spatial-domain basis function refinement as described herein. For example, the communication manager 520, the receiver 510, the transmitter 515, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0160] In some examples, the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic components, discrete hardware components, or any combination thereof that is configured to or otherwise supports components for performing the functions described in the present disclosure. In some examples, the processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0161] Additionally or alternatively, in some examples, the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting components for performing the functions described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0162] In some examples, communication manager 520 may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with receiver 510, transmitter 515, or both. For example, communication manager 520 may receive information from receiver 510, transmit information to transmitter 515, or be integrated with receiver 510, transmitter 515, or both to obtain information, output information, or perform various other operations as described herein.

[0163] According to examples as disclosed herein, the communication manager 520 may support wireless communications at a UE (e.g., device 505). For example, the communication manager 520 may be configured to or otherwise support components for receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity. The communication manager 520 may be configured to or otherwise support components for sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The communication manager 520 may be configured to or otherwise support components for receiving a second message from the network entity based on the partial CSI report.

[0164] By including or configuring a communication manager 520 according to examples as described herein, a device 505 (e.g., a processor controlling or otherwise coupled to a receiver 510, a transmitter 515, a communication manager 520, or a combination thereof) may support techniques for more efficiently utilizing communication resources.

[0165] Figure 6A block diagram 600 of a device 605 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 605 may be an example of aspects of the device 505 or UE 115 as described herein. The device 605 may include a receiver 610, a transmitter 615, and a communication manager 620. The device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0166] The receiver 610 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques for spatial domain basis function refinement). The information may be communicated to other components of the device 605. The receiver 610 may utilize a single antenna or a collection of multiple antennas.

[0167] The transmitter 615 may provide means for transmitting signals generated by other components of the device 605. For example, the transmitter 615 may transmit information associated with various information channels (e.g., control channels related to techniques for spatial domain basis function refinement, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 615 may be co-located with the receiver 610 in a transceiver component. The transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0168] The device 605 or its various components may be examples of components for performing various aspects of the techniques for spatial domain basis function refinement as described herein. For example, the communication manager 620 may include a configuration indication component 625, a CSI reporting component 630, a message component 635, or any combination thereof. The communication manager 620 may be an example of various aspects of the communication manager 520 as described herein. In some examples, the communication manager 620 or its various components may be configured to use or otherwise cooperate with the receiver 610, the transmitter 615, or both to perform various operations (e.g., receive, obtain, monitor, output, send). For example, the communication manager 620 may receive information from the receiver 610, transmit information to the transmitter 615, or be integrated with the receiver 610, the transmitter 615, or both to obtain information, output information, or perform various other operations as described herein.

[0169] According to examples as disclosed herein, the communication manager 620 may support wireless communications at a UE (e.g., device 605). The configuration indication component 625 may be configured to or otherwise support means for receiving a first message from a network entity indicating a configuration for reporting spatial domain basis function updates to the network entity. The CSI reporting component 630 may be configured to or otherwise support means for sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The message component 635 may be configured to or otherwise support means for receiving a second message from the network entity based on the partial CSI report.

[0170] Figure 7 A block diagram 700 of a communication manager 720 supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is shown. The communication manager 720 may be an example of aspects of the communication manager 520, the communication manager 620, or both as described herein. The communication manager 720 or its various components may be examples of components for performing various aspects of the techniques for spatial domain basis function refinement as described herein. For example, the communication manager 720 may include a configuration indication component 725, a CSI reporting component 730, a message component 735, an update indication component 740, an update request component 745, an offset indication component 750, a shift indication component 755, a coefficient indication component 760, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0171] According to examples as disclosed herein, the communication manager 720 may support wireless communications at a UE. The configuration indication component 725 may be configured to or otherwise support means for receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity. The CSI reporting component 730 may be configured to or otherwise support means for sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The message component 735 may be configured to or otherwise support means for receiving a second message from the network entity based on the partial CSI report.

[0172] In some examples, update indication component 740 may be configured to or otherwise support means for receiving a third message from a network entity indicating that the UE reports an update to the set of spatial domain basis functions, wherein sending the partial CSI report is based on the received third message. In some examples, to support receiving the first message, update indication component 740 may be configured to or otherwise support means for receiving an indication of an update to the set of reported spatial domain basis functions relative to a full CSI report or a previous partial CSI report, wherein sending the partial CSI report indicating the update is based on the received indication.

[0173] In some examples, update request component 745 may be configured as or otherwise support components for sending a third message to a network entity requesting reporting of an update to a set of spatial domain basis functions, wherein sending the partial CSI report is based on the sent third message.

[0174] In some examples, to support sending a partial CSI report, the offset indication component 750 may be configured as or otherwise support components for sending an indication of a set of offsets to be applied to a set of spatial domain basis functions, wherein each offset in the set of offsets corresponds to a corresponding spatial domain basis function in the set of spatial domain basis functions, and wherein the set of offsets indicates an update to the set of spatial domain basis functions. In some examples, each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with the corresponding spatial domain basis function and a second value corresponding to a zenith angle associated with the corresponding spatial domain basis function.

[0175] In some examples, to support sending a partial CSI report, the shift indication component 755 may be configured or otherwise support means for sending an indication of a shift of a position of a set of coefficients associated with a set of spatial domain basis functions, wherein the shift of the position of the set of coefficients indicates an update to the set of spatial domain basis functions. In some examples, the set of coefficients has a non-zero value.

[0176] In some examples, to support sending an indication of a shift in the positioning of a set of coefficients, the shift indication component 755 may be configured as or otherwise support means for sending a set of bits indicating a value of an index corresponding to a shift in the positioning of a set of coefficients.

[0177] In some examples, to support sending an indication of a positioned shift of a set of coefficients, the shift indication component 755 may be configured as or otherwise support components for sending an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient difference indicates a shift in the value and the positioning of the corresponding coefficient in the set of coefficients.

[0178] In some examples, to support sending a full CSI report and a partial CSI report, CSI reporting component 730 can be configured to or otherwise support means for sending a full CSI report at a first time instance and sending a partial CSI report at a second time instance after the first time instance, wherein the second time instance is based on a prediction performed at the UE. In some examples, the prediction is based on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0179] In some examples, to support sending a partial CSI report, coefficient indicating component 760 may be configured or otherwise support means for receiving a third message indicating a set of multiple coefficient sets from a network entity, wherein each coefficient set in the indicated set of multiple coefficient sets corresponds to a respective set of spatial-domain basis functions. In some examples, to support sending a partial CSI report, coefficient indicating component 760 may be configured or otherwise support means for sending an indication of one or more coefficient sets in the indicated set of multiple coefficient sets to the network entity based on the received third message, wherein the one or more coefficient sets indicate updates to the set of spatial-domain basis functions.

[0180] In some examples, to support sending an indication of one or more coefficient sets, coefficient indication component 760 may be configured as or otherwise support components for sending an indication of a differential coefficient set, wherein each differential coefficient in the differential coefficient set indicates a coefficient difference between a coefficient in a first coefficient set in the indicated set of multiple coefficient sets and a corresponding coefficient in a second coefficient set in the indicated set of multiple coefficient sets.

[0181] Figure 8 A diagram of a system 800 including a device 805 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 805 may be an example of a device 505, a device 605, or a UE 115 as described herein, or include components thereof. The device 805 may communicate (e.g., wirelessly) with one or more of the network entities 105, one or more of the UEs 115, or any combination thereof. The device 805 may include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 820, an input / output (I / O) controller (such as the I / O controller 810), a transceiver 815, an antenna 825, a memory 830, a code 835, and a processor 840. These components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 845).

[0182] I / O controller 810 can manage input signals and output signals of device 805. I / O controller 810 can also manage peripheral devices that are not integrated into device 805. In some cases, I / O controller 810 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 810 can utilize an operating system, such as or another known operating system. Additionally or alternatively, I / O controller 810 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 810 may be implemented as part of a processor (such as processor 840). In some cases, a user may interact with device 805 via I / O controller 810 or via hardware components controlled by I / O controller 810.

[0183] In some cases, the device 805 may include an antenna 825. However, in some other cases, the device 805 may have more than one of the antennas 825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 815 may communicate bidirectionally via one or more of the antennas 825, a wired or wireless link, as described herein. For example, the transceiver 815 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 815 may also include a modem for: modulating packets; providing the modulated packets to one or more of the antennas 825 for transmission; and demodulating packets received from one or more of the antennas 825. The transceiver 815 or the transceiver 815 and one or more of the antennas 825 may be examples of the transmitter 515, the transmitter 615, the receiver 510, the receiver 610, or any combination thereof or components thereof as described herein.

[0184] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code (such as code 835) including instructions that, when executed by the processor 840, cause the device 805 to perform various functions described herein. The code 835 may be stored in a non-transitory computer-readable medium such as a system memory or another type of memory. In some cases, the code 835 may not be directly executable by the processor 840, but may (for example, when compiled and executed) cause the computer to perform the functions described herein. In some cases, the memory 830 may also contain, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0185] The processor 840 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., a memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks that support techniques for spatial domain basis function refinement). For example, the device 805 or a component of the device 805 may include a processor 840 and a memory 830 coupled to or coupled to the processor 840, and the processor 840 and the memory 830 are configured to perform the various functions described herein.

[0186] According to examples as disclosed herein, the communication manager 820 may support wireless communications at a UE (e.g., device 805). For example, the communication manager 820 may be configured to or otherwise support components for receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity. The communication manager 820 may be configured to or otherwise support components for sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The communication manager 820 may be configured to or otherwise support components for receiving a second message from the network entity based on the partial CSI report.

[0187] By including or configuring a communication manager 820 according to examples as described herein, the device 805 can support techniques for improving communication reliability, reducing latency, more efficiently utilizing communication resources, and improving coordination between devices.

[0188] In some examples, the communication manager 820 may be configured to perform various operations (e.g., receive, monitor, transmit) using or otherwise cooperating with the transceiver 815, one or more of the antennas 825, or any combination thereof. Although the communication manager 820 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 820 may be supported or performed by the processor 840, the memory 830, the code 835, or any combination thereof. For example, the code 835 may include instructions that are executable by the processor 840 to cause the device 805 to perform various aspects of the techniques for spatial domain basis function refinement as described herein, or the processor 840 and the memory 830 may be otherwise configured to perform or support such operations.

[0189] Fig. 9 A block diagram 900 of a device 905 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 905 may be an example of aspects of the network entity 105 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0190] Receiver 910 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be communicated to other components of device 905. In some examples, receiver 910 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 910 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0191] The transmitter 915 may provide means for outputting (e.g., sending, providing, conveying, transmitting) information generated by other components of the device 905. For example, the transmitter 915 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 915 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 915 may support outputting information by sending signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 915 and the receiver 910 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0192] The communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of the techniques for spatial domain basis function refinement as described herein. For example, the communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0193] In some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic components, discrete hardware components, or any combination thereof that is configured as or otherwise supports components for performing the functions described in the present disclosure. In some examples, a processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0194] Additionally or alternatively, in some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting components for performing the functions described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0195] In some examples, the communication manager 920 may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with the receiver 910, the transmitter 915, or both. For example, the communication manager 920 may receive information from the receiver 910, transmit information to the transmitter 915, or be integrated with the receiver 910, the transmitter 915, or both to obtain information, output information, or perform various other operations as described herein.

[0196] According to examples as disclosed herein, the communication manager 920 may support wireless communications at a network entity (e.g., device 905). For example, the communication manager 920 may be configured to or otherwise support components for outputting a first message indicating a configuration for reporting spatial domain basis function updates to the network entity. The communication manager 920 may be configured to or otherwise support components for obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The communication manager 920 may be configured to or otherwise support components for outputting a second message based on the partial CSI report.

[0197] By including or configuring a communication manager 920 according to examples as described herein, a device 905 (e.g., a processor controlling or otherwise coupled to a receiver 910, a transmitter 915, a communication manager 920, or a combination thereof) may support techniques for more efficiently utilizing communication resources.

[0198] Fig.10 A block diagram 1000 of a device 1005 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 1005 may be an example of aspects of the device 905 or network entity 105 as described herein. The device 1005 may include a receiver 1010, a transmitter 1015, and a communication manager 1020. The device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0199] Receiver 1010 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be communicated to other components of device 1005. In some examples, receiver 1010 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 1010 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0200] The transmitter 1015 may provide means for outputting (e.g., sending, providing, conveying, transmitting) information generated by other components of the device 1005. For example, the transmitter 1015 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 1015 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 1015 may support outputting information by sending signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1015 and the receiver 1010 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0201] Device 1005 or its various components may be examples of components for performing various aspects of the techniques for spatial domain basis function refinement as described herein. For example, communication manager 1020 may include configuration component 1025, reporting component 1030, message output component 1035, or any combination thereof. Communication manager 1020 may be an example of various aspects of communication manager 920 as described herein. In some examples, communication manager 1020 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise in conjunction with receiver 1010, transmitter 1015, or both. For example, communication manager 1020 may receive information from receiver 1010, transmit information to transmitter 1015, or integrate with receiver 1010, transmitter 1015, or both in combination to obtain information, output information, or perform various other operations as described herein.

[0202] According to examples as disclosed herein, the communication manager 1020 may support wireless communications at a network entity (e.g., device 1005). The configuration component 1025 may be configured to or otherwise support means for outputting a first message indicating a configuration for reporting spatial domain basis function updates to the network entity. The reporting component 1030 may be configured to or otherwise support means for obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The message output component 1035 may be configured to or otherwise support means for outputting a second message based on the partial CSI report.

[0203] Fig.11A block diagram 1100 of a communication manager 1120 supporting techniques for spatial domain basis function refinement in accordance with various aspects of the present disclosure is shown. The communication manager 1120 can be an example of aspects of the communication manager 920, the communication manager 1020, or both as described herein. The communication manager 1120 or its various components can be examples of means for performing various aspects of the techniques for spatial domain basis function refinement as described herein. For example, the communication manager 1120 can include a configuration component 1125, a reporting component 1130, a message output component 1135, a report request component 1140, an offset component 1145, a shift component 1150, a coefficient component 1155, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses), which communication may include communication within a protocol layer of a protocol stack, communication associated with a logical channel of the protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with the network entity 105, between devices, components, or virtualized components associated with the network entity 105), or any combination thereof.

[0204] According to examples as disclosed herein, the communication manager 1120 may support wireless communications at a network entity. The configuration component 1125 may be configured to or otherwise support means for outputting a first message indicating a configuration for reporting spatial domain basis function updates to the network entity. The reporting component 1130 may be configured to or otherwise support means for obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The message output component 1135 may be configured to or otherwise support means for outputting a second message based on the partial CSI report.

[0205] In some examples, reporting component 1130 may be configured to or otherwise support means for outputting a third message indicating that the UE reports an update to the set of spatial domain basis functions, wherein obtaining the partial CSI report is based on outputting the third message. In some examples, to support outputting the first message, reporting component 1130 may be configured to or otherwise support means for outputting an indication of an update to the UE reporting the set of spatial domain basis functions relative to a full CSI report or a previous partial CSI report, wherein obtaining the partial CSI report indicating the update is based on outputting the indication.

[0206] In some examples, report request component 1140 may be configured to or otherwise support components for obtaining a third message from the UE comprising a request to report an update to a set of spatial domain basis functions, wherein obtaining the partial CSI report is based on outputting the third message.

[0207] In some examples, to support obtaining a partial CSI report, the offset component 1145 may be configured to or otherwise support means for obtaining an indication of a set of offsets to be applied to a set of spatial-domain basis functions, wherein each offset in the set of offsets corresponds to a corresponding spatial-domain basis function in the set of spatial-domain basis functions, and wherein the set of offsets indicates an update to the set of spatial-domain basis functions. In some examples, each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with the corresponding spatial-domain basis function and a second value corresponding to a zenith angle associated with the corresponding spatial-domain basis function.

[0208] In some examples, to support obtaining a partial CSI report, the shift component 1150 may be configured to or otherwise support means for obtaining an indication of a shift of a position of a set of coefficients associated with a set of spatial domain basis functions, wherein the shift of the position of the set of coefficients indicates an update to the set of spatial domain basis functions. In some examples, the set of coefficients has a non-zero value.

[0209] In some examples, to support obtaining an indication of a positioned shift of a set of coefficients, shift component 1150 may be configured as or otherwise support means for obtaining a set of bits indicating a value of an index corresponding to a positioned shift of a set of coefficients.

[0210] In some examples, to support obtaining an indication of a positioned shift of a set of coefficients, shift component 1150 may be configured as or otherwise support components for obtaining an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient difference indicates a shift in the value and the positioned shift of the corresponding coefficient in the set of coefficients.

[0211] In some examples, to support obtaining a full CSI report and a partial CSI report, reporting component 1130 can be configured as or otherwise support means for obtaining a full CSI report at a first time instance and obtaining a partial CSI report at a second time instance after the first time instance, wherein the second time instance is based on the first time instance and a prediction performed at the UE. In some examples, the prediction is based on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0212] In some examples, to support obtaining a partial CSI report, coefficient component 1155 may be configured or otherwise support means for outputting a third message indicating a set of multiple coefficient sets, wherein each coefficient set in the indicated set of multiple coefficient sets corresponds to a respective set of spatial-domain basis functions. In some examples, to support obtaining a partial CSI report, coefficient component 1155 may be configured or otherwise support means for obtaining an indication of one or more coefficient sets in the indicated set of multiple coefficient sets based on outputting the third message, wherein the one or more coefficient sets indicate updates to the set of spatial-domain basis functions.

[0213] In some examples, to support obtaining an indication of one or more sets of coefficients, coefficient component 1155 may be configured as or otherwise support components for obtaining an indication of a set of differential coefficients, wherein each differential coefficient in the set of differential coefficients indicates a coefficient difference between a coefficient in a first set of coefficients in the indicated set of multiple sets of coefficients and a corresponding coefficient in a second set of coefficients in the indicated set of multiple sets of coefficients.

[0214] Fig.12 A diagram of a system 1200 including a device 1205 supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The device 1205 may be an example of a device 905, a device 1005, or a network entity 105 as described herein, or include components thereof. The device 1205 may communicate with one or more network entities in the network entity 105, one or more UEs in the UE 115, or any combination thereof, which may include communication through one or more wired interfaces, through one or more wireless interfaces, or any combination thereof. The device 1205 may include components that support output and acquisition of communications, such as a communication manager 1220, a transceiver 1210, an antenna 1215, a memory 1225, a code 1230, and a processor 1235. These components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1240).

[0215] The transceiver 1210 may support bidirectional communication via a wired link, a wireless link, or both as described herein. In some examples, the transceiver 1210 may include a wired transceiver and may communicate bidirectionally with another wired transceiver. Additionally or alternatively, in some examples, the transceiver 1210 may include a wireless transceiver and may communicate bidirectionally with another wireless transceiver. In some examples, the device 1205 may include one or more of the antennas 1215, which may be capable of sending or receiving wireless transmissions (e.g., concurrently). The transceiver 1210 may also include a modem for: modulating a signal; providing the modulated signal for transmission (e.g., via one or more of the antennas 1215, via a wired transmitter); receiving a modulated signal (e.g., from one or more of the antennas 1215, from a wired receiver); and demodulating a signal. In some examples, the transceiver 1210 may include one or more interfaces, such as one or more interfaces coupled to one or more of the antennas 1215 configured to support various receiving or obtaining operations or one or more interfaces coupled to one or more of the antennas 1215 configured to support various sending or output operations, or a combination thereof. In some examples, the transceiver 1210 may include or be configured to be coupled to one or more processors or memory components that are operable to: perform or support operations based on received or obtained information or signals; or generate information or other signals for transmission or other output, or any combination thereof. In some examples, the transceiver 1210, or the transceiver 1210 and one or more of the antennas 1215, or the transceiver 1210 and one or more of the antennas 1215 and one or more processors or memory components (e.g., processor 1235, or memory 1225, or both) may be included in a chip or chip assembly installed in the device 1205. In some examples, the transceiver may be operable to support communications via one or more communication links (eg, communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0216] Memory 1225 may include RAM and ROM. Memory 1225 may store computer-readable, computer-executable code (such as code 1230) including instructions that, when executed by processor 1235, cause device 1205 to perform various functions described herein. Code 1230 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1230 may not be directly executable by processor 1235, but may (e.g., when compiled and executed) cause a computer to perform the functions described herein. In some cases, memory 1225 may also include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0217] Processor 1235 may include an intelligent hardware device (e.g., a general-purpose processor, DSP, ASIC, CPU, FPGA, microcontroller, programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1235 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1235. Processor 1235 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1225) to enable device 1205 to perform various functions (e.g., functions or tasks supporting techniques for spatial domain basis function refinement). For example, device 1205 or a component of device 1205 may include processor 1235 and memory 1225 coupled to processor 1235, and processor 1235 and memory 1225 are configured to perform various functions described herein. Processor 1235 may be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software such as an operating system, a virtual machine, or a container instance), which may host functions for performing functions of device 1205 (e.g., by executing code 1230). Processor 1235 may be any suitable processor or processors capable of executing scripts or instructions of one or more software programs stored in device 1205 (such as within memory 1225).

[0218] In some examples, the processor 1235 may be a component of a processing system. A processing system may refer to a system or a series of machines or components that receives inputs and processes these inputs to produce an output set (which may be passed to other systems or components (e.g., of the device 1205)). For example, the processing system of the device 1205 may refer to a system including various other components or subcomponents of the device 1205, such as the processor 1235, or the transceiver 1210, or the communication manager 1220, or other components or combinations of components of the device 1205. The processing system of the device 1205 may interface with other components of the device 1205, and may process information (such as inputs or signals) received from other components, or output information to other components. For example, a chip or modem of the device 1205 may include a processing system and one or more interfaces for outputting information or for obtaining information or both. One or more interfaces may be implemented as or otherwise include a first interface configured to output information and a second interface configured to obtain information, or the same interface configured to output information and obtain information, as well as other specific implementations.

[0219] In some examples, one or more interfaces may refer to an interface between a processing system of a chip or modem and a transmitter, so that the device 1205 can send information output from the chip or modem. Additionally or alternatively, in some examples, one or more interfaces may refer to an interface between a processing system of a chip or modem and a receiver, so that the device 1205 can obtain information or signal input, and the information can be passed to the processing system. A person of ordinary skill in the art will readily recognize that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0220] In some examples, bus 1240 may support communications of protocol layers (e.g., within a protocol layer) of a protocol stack. In some examples, bus 1240 may support communications associated with logical channels of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within components of device 1205, or communications performed between different components of device 1205 that may be co-located or may be located in different locations (e.g., where device 1205 may refer to a system in which one or more of communication manager 1220, transceiver 1210, memory 1225, code 1230, and processor 1235 may be located in one of the different components or divided between the different components).

[0221] In some examples, the communication manager 1220 may manage aspects of communications with the core network 130 (e.g., via one or more wired or wireless backhaul links). For example, the communication manager 1220 may manage the transfer of data communications for client devices, such as one or more UEs in the UE 115. In some examples, the communication manager 1220 may manage communications with other network entities in the network entity 105 and may include a controller or scheduler for controlling communications with the UE 115 in cooperation with the other network entities in the network entity 105. In some examples, the communication manager 1220 may support an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between the network entities 105.

[0222] According to examples as disclosed herein, the communication manager 1220 may support wireless communications at a network entity (e.g., device 1205). For example, the communication manager 1220 may be configured to or otherwise support components for outputting a first message indicating a configuration for reporting spatial domain basis function updates to the network entity. The communication manager 1220 may be configured to or otherwise support components for obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The communication manager 1220 may be configured to or otherwise support components for outputting a second message based on the partial CSI report.

[0223] By including or configuring a communications manager 1220 according to examples as described herein, the device 1205 can support techniques for improving communications reliability, reducing latency, more efficiently utilizing communications resources, and improving coordination between devices.

[0224] In some examples, the communication manager 1220 may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with the transceiver 1210, one or more of the antennas 1215 (e.g., where applicable), or any combination thereof. Although the communication manager 1220 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1220 may be supported or performed by the transceiver 1210, the processor 1235, the memory 1225, the code 1230, or any combination thereof. For example, the code 1230 may include instructions that are executable by the processor 1235 to cause the device 1205 to perform various aspects of the techniques for spatial domain basis function refinement as described herein, or the processor 1235 and the memory 1225 may be otherwise configured to perform or support such operations.

[0225] Fig.13 A flow chart illustrating a method 1300 for supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE or a component thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE or a component thereof as described in reference to Figures 1 to 8 The described UE 115 may be performed. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0226] At 1305, the method may include receiving a first message from a network entity indicating a configuration for reporting spatial domain basis function updates to the network entity. The operations of 1305 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1305 may be performed as described in reference to Figure 7 The described configuration instructs component 725 to execute.

[0227] At 1310, the method may include sending a full CSI report and a partial CSI report to a network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The operations of 1310 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1310 may be performed as described in reference to Figure 7 The CSI reporting component 730 is used to perform.

[0228] At 1315, the method may include receiving a second message from the network entity based on the partial CSI report. The operations of 1315 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1315 may be performed as described in reference to Figure 7 The message component 735 is used to execute.

[0229] Fig.14 A flow chart illustrating a method 1400 for supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by a UE or a component thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE or a component thereof as described in reference to Figures 1 to 8 The described UE 115 may be performed. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0230] At 1405, the method may include receiving a first message from a network entity indicating a configuration for reporting spatial domain basis function updates to the network entity. The operations of 1405 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1405 may be performed as described in reference to Figure 7 The described configuration instructs component 725 to execute.

[0231] At 1410, the method may include receiving a third message from the network entity indicating that the UE reports an update to the set of spatial domain basis functions. The operations of 1410 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1410 may be performed as described in reference to Figure 7 The update instruction component 740 is executed.

[0232] At 1415, the method may include sending a full CSI report and a partial CSI report to the network entity based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report, wherein sending the partial CSI report is based on the received third message. The operations of 1415 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1415 may be performed as described in reference to Figure 7 The CSI reporting component 730 is used to perform.

[0233] At 1420, the method may include receiving a second message from the network entity based on the partial CSI report. The operations of 1420 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1420 may be performed as described in reference to Figure 7 The message component 735 is used to execute.

[0234] Fig.15 A flow chart illustrating a method 1500 for supporting techniques for spatial domain basis function refinement according to various aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1500 may be implemented by a network entity or a component thereof as described in reference to Figures 1 to 4 as well as Figures 9 to 12 In some examples, the network entity may execute an instruction set to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform various aspects of the described functions.

[0235] At 1505, the method may include outputting a first message indicating a configuration for reporting spatial domain basis function updates to a network entity. The operations of 1505 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1505 may be performed as described in reference to Fig.11The configuration component 1125 is used to execute.

[0236] At 1510, the method may include obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report. The operations of 1510 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1510 may be performed as described in reference to Fig.11 The described reporting component 1130 is executed.

[0237] At 1515, the method may include outputting a second message based on the partial CSI report. The operations of 1515 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1515 may be described with reference to Fig.11 The message output component 1135 is used to execute.

[0238] Fig.16 1600 is a flowchart illustrating a method 1600 that supports techniques for spatial domain basis function refinement according to various aspects of the present disclosure. The operations of the method 1600 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1600 may be implemented by a network entity or a component thereof as described in reference to Figures 1 to 4 as well as Figures 9 to 12 In some examples, the network entity may execute an instruction set to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform various aspects of the described functions.

[0239] At 1605, the method may include outputting a first message indicating a configuration for reporting spatial domain basis function updates to a network entity. The operations of 1605 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed as described in reference to Fig.11 The configuration component 1125 is used to execute.

[0240] At 1610, the method may include obtaining from the UE a third message including a request to report an update to the set of spatial domain basis functions. The operations of 1610 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1610 may be performed as described in reference to Fig.11 The report request component 1140 is used to execute.

[0241] At 1615, the method may include obtaining a full CSI report and a partial CSI report based on the indicated configuration, the full CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the full CSI report or a previous partial CSI report, wherein obtaining the partial CSI report is based on outputting a third message. The operations of 1615 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed as described in reference to Fig.11 The described reporting component 1130 is executed.

[0242] At 1620, the method may include outputting a second message based on the partial CSI report. The operations of 1620 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1620 may be described with reference to Fig.11 The message output component 1135 is used to execute.

[0243] The following provides an overview of various aspects of the disclosure:

[0244] Aspect 1: A method for wireless communication at a UE, the method comprising: receiving a first message from a network entity indicating a configuration for reporting a spatial domain basis function update to the network entity; sending a complete CSI report and a partial CSI report to the network entity based at least in part on the indicated configuration, the complete CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the complete CSI report or a previous partial CSI report; and receiving a second message from the network entity based at least in part on the partial CSI report.

[0245] Aspect 2: According to the method of Aspect 1, the method also includes: receiving a third message from the network entity indicating that the UE reports the update to the set of spatial domain basis functions, wherein sending the partial CSI report is at least partially based on the received third message.

[0246] Aspect 3: A method according to any one of Aspects 1 to 2, wherein receiving the first message includes: receiving an indication of reporting the update of the set of spatial domain basis functions relative to the complete CSI report or the previous partial CSI report, wherein sending the partial CSI report indicating the update is at least partially based on the received indication.

[0247] Aspect 4: According to the method described in any one of Aspects 1 to 3, the method further includes: sending a third message to the network entity requesting a report of the update to the set of spatial domain basis functions, wherein sending the partial CSI report is at least partially based on the sent third message.

[0248] Aspect 5: A method according to any one of Aspects 1 to 4, wherein sending the partial CSI report includes: sending an indication of a set of offsets to be applied to the set of spatial domain basis functions, wherein each offset in the set of offsets corresponds to a corresponding spatial domain basis function in the set of spatial domain basis functions, and wherein the set of offsets indicates the update to the set of spatial domain basis functions.

[0249] Aspect 6: The method according to Aspect 5, wherein each offset in the offset set identifies a first value corresponding to an azimuth angle associated with the corresponding space-domain basis function and a second value corresponding to a zenith angle associated with the corresponding space-domain basis function.

[0250] Aspect 7: A method according to any one of Aspects 1 to 4, wherein sending the partial CSI report includes: sending an indication of a shift in the positioning of a coefficient set associated with the set of spatial domain basis functions, wherein the shift in the positioning of the coefficient set indicates the update to the set of spatial domain basis functions.

[0251] Aspect 8: The method according to aspect 7, wherein the set of coefficients has non-zero values.

[0252] Aspect 9: A method according to any one of Aspects 7 to 8, wherein sending the indication of the shift of the positioning of the coefficient set includes: sending a bit set indicating the value of the index corresponding to the shift of the positioning of the coefficient set.

[0253] Aspect 10: A method according to any one of Aspects 7 to 8, wherein sending the indication of the shift of the positioning of the coefficient set includes: sending an indication of a differential coefficient set, wherein each differential coefficient in the differential coefficient set corresponds to a coefficient difference relative to a corresponding coefficient in the coefficient set, and wherein the coefficient difference indicates a shift of the value and the shift of the positioning of the corresponding coefficient in the coefficient set.

[0254] Aspect 11: A method according to any one of Aspects 1 to 10, wherein sending the complete CSI report and the partial CSI report includes: sending the complete CSI report at a first time instance and sending the partial CSI report at a second time instance after the first time instance, wherein the second time instance is at least partially based on a prediction performed at the UE.

[0255] Aspect 12: The method according to aspect 11, wherein the prediction is based at least in part on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0256] Aspect 13: A method according to any one of Aspects 1 to 4, 11 and 12, wherein sending the partial CSI report includes: receiving a third message indicating multiple coefficient sets from the network entity, wherein each coefficient set in the indicated multiple coefficient sets corresponds to a corresponding spatial domain basis function set; and sending an indication of one or more coefficient sets in the indicated multiple coefficient sets to the network entity based at least in part on the received third message, wherein the one or more coefficient sets indicate the update to the spatial domain basis function set.

[0257] Aspect 14: A method according to Aspect 13, wherein sending the indication of the one or more coefficient sets includes: sending an indication of a differential coefficient set, wherein each differential coefficient in the differential coefficient set indicates a coefficient difference between a coefficient in a first coefficient set in the indicated multiple coefficient sets and a corresponding coefficient in a second coefficient set in the indicated multiple coefficient sets.

[0258] Aspect 15: A method for performing wireless communications at a network entity, the method comprising: outputting a first message indicating a configuration for reporting spatial domain basis function updates to the network entity; obtaining a complete CSI report and a partial CSI report based at least in part on the indicated configuration, the complete CSI report indicating at least a set of spatial domain basis functions, and the partial CSI report indicating an update of the set of spatial domain basis functions relative to the complete CSI report or a previous partial CSI report; and outputting a second message based at least in part on the partial CSI report.

[0259] Aspect 16: According to the method of aspect 15, the method also includes: outputting a third message instructing the UE to report the update to the set of spatial domain basis functions, wherein obtaining the partial CSI report is at least partially based on outputting the third message.

[0260] Aspect 17: A method according to any one of Aspects 15 to 16, wherein outputting the first message includes: outputting an indication of the update of the set of spatial domain basis functions reported to the UE relative to the complete CSI report or the previous partial CSI report, wherein obtaining the partial CSI report indicating the update is at least partially based on outputting the indication.

[0261] Aspect 18: According to any one of Aspects 15 to 17, the method further includes: obtaining from the UE a third message including a request to report the update of the set of spatial domain basis functions, wherein obtaining the partial CSI report is at least partially based on outputting the third message.

[0262] Aspect 19: A method according to any one of Aspects 15 to 18, wherein obtaining the partial CSI report includes: obtaining an indication of a set of offsets to be applied to the set of spatial domain basis functions, wherein each offset in the set of offsets corresponds to a corresponding spatial domain basis function in the set of spatial domain basis functions, and wherein the set of offsets indicates the update to the set of spatial domain basis functions.

[0263] Aspect 20: The method according to Aspect 19, wherein each offset in the offset set identifies a first value corresponding to an azimuth angle associated with the corresponding space-domain basis function and a second value corresponding to a zenith angle associated with the corresponding space-domain basis function.

[0264] Aspect 21: A method according to any one of Aspects 15 to 18, wherein obtaining the partial CSI report includes: obtaining an indication of a shift in the positioning of a coefficient set associated with the set of spatial domain basis functions, wherein the shift in the positioning of the coefficient set indicates the update to the set of spatial domain basis functions.

[0265] Aspect 22: The method according to aspect 21, wherein the set of coefficients has non-zero values.

[0266] Aspect 23: A method according to any one of Aspects 21 to 22, wherein obtaining the indication of the shift of the positioning of the coefficient set includes: obtaining a bit set indicating the value of the index corresponding to the shift of the positioning of the coefficient set.

[0267] Aspect 24: A method according to any one of Aspects 21 to 22, wherein obtaining the indication of the shift of the positioning of the coefficient set includes: obtaining an indication of a differential coefficient set, wherein each differential coefficient in the differential coefficient set corresponds to a coefficient difference relative to a corresponding coefficient in the coefficient set, and wherein the coefficient difference indicates a shift of the value and the shift of the positioning of the corresponding coefficient in the coefficient set.

[0268] Aspect 25: A method according to any one of Aspects 15 to 24, wherein obtaining the complete CSI report and the partial CSI report includes: obtaining the complete CSI report at a first time instance and obtaining the partial CSI report at a second time instance after the first time instance, wherein the second time instance is at least partially based on the first time instance and a prediction performed at the UE.

[0269] Aspect 26: The method according to aspect 25, wherein the prediction is based at least in part on a CSI measurement rate configured at the UE, a CSI reporting rate configured at the UE, or both.

[0270] Aspect 27: A method according to any one of Aspects 15 to 18, 25 and 26, wherein obtaining the partial CSI report includes: outputting a third message indicating multiple coefficient sets, wherein each coefficient set in the indicated multiple coefficient sets corresponds to a corresponding spatial domain basis function set; and obtaining an indication of one or more coefficient sets in the indicated multiple coefficient sets based at least in part on outputting the third message, wherein the one or more coefficient sets indicate the update to the spatial domain basis function set.

[0271] Aspect 28: A method according to Aspect 27, wherein obtaining the indication of the one or more coefficient sets includes: obtaining an indication of a differential coefficient set, wherein each differential coefficient in the differential coefficient set indicates a coefficient difference between a coefficient in a first coefficient set in the indicated multiple coefficient sets and a corresponding coefficient in a second coefficient set in the indicated multiple coefficient sets.

[0272] Aspect 29: An apparatus for performing wireless communications at a UE, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 1 to 14.

[0273] Aspect 30: An apparatus for wireless communication at a UE, the apparatus comprising at least one component for performing a method according to any one of aspects 1 to 14.

[0274] Aspect 31: A non-transitory computer-readable medium storing a code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method according to any one of aspects 1 to 14.

[0275] Aspect 32: An apparatus for wireless communication at a network entity, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 15 to 28.

[0276] Aspect 33: An apparatus for wireless communication at a network entity, the apparatus comprising at least one component for performing a method according to any one of aspects 15 to 28.

[0277] Aspect 34: A non-transitory computer-readable medium storing code for wireless communication at a network entity, the code comprising instructions executable by a processor to perform the method according to any one of aspects 15 to 28.

[0278] It should be noted that the methods described herein describe possible implementations, and that the various operations and steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0279] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0280] The information and signals described herein may be represented using any of a variety of different technologies and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the specification may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0281] The various blocks and components described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0282] The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functions may be stored as one or more instructions or codes of a computer-readable medium, or sent using one or more instructions or codes of a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these items. Features that implement the functions may also be physically located at different locations, including being distributed so that the functions are implemented at different physical locations.

[0283] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to be transferred from one position to another position.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.By way of example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage device, disk storage device or other magnetic storage device, or can be used for carrying or storing desired program code parts and any other non-transient medium that can be accessed by general or special-purpose computer or general or special-purpose processor in the form of instruction or data structure.Moreover, any connection is appropriately referred to as computer-readable medium.For example, if software is sent from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are included in the definition of computer-readable medium. Disks and optical disks as used herein include CDs, laser optical disks, optical optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks. Disks can reproduce data magnetically, and optical disks can reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0284] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0285] The term "determining" encompasses a variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database or other data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data stored in a memory), etc. Additionally, "determining" may include parsing, obtaining, selecting, choosing, establishing, and other such similar actions.

[0286] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number to distinguish between the similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number, regardless of the second or other subsequent reference numbers.

[0287] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The specific embodiments include specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0288] The description herein is provided to enable one of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), the method comprising: receiving, from a network entity, a first message indicating a configuration for reporting spatial domain basis function updates to the network entity; sending, based at least in part on the indicated configuration, a complete channel state information report and a partial channel state information report to the network entity, the complete channel state information report indicating at least a set of spatial domain basis functions and the partial channel state information report indicating an update of the set of spatial domain basis functions relative to the complete channel state information report or a previous partial channel state information report; as well as A second message is received from the network entity based at least in part on the partial channel state information report.

2. The method according to claim 1, further comprising: A third message is received from the network entity instructing the UE to report the update to the set of spatial domain basis functions, wherein sending the partial channel state information report is based at least in part on the received third message.

3. The method of claim 1 , wherein receiving the first message comprises: An indication is received to report the update to the set of spatial domain basis functions relative to the complete channel state information report or the previous partial channel state information report, wherein sending the partial channel state information report indicating the update is based at least in part on the received indication.

4. The method according to claim 1, further comprising: A third message is sent to the network entity requesting reporting of the update to the set of spatial domain basis functions, wherein sending the partial channel state information report is based at least in part on the sent third message.

5. The method of claim 1 , wherein sending the partial channel state information report comprises: An indication of a set of offsets to be applied to the set of spatial-domain basis functions is sent, wherein each offset in the set of offsets corresponds to a respective spatial-domain basis function in the set of spatial-domain basis functions, and wherein the set of offsets indicates the update to the set of spatial-domain basis functions.

6. The method of claim 5, wherein each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with the corresponding space-domain basis function and a second value corresponding to a zenith angle associated with the corresponding space-domain basis function.

7. The method of claim 1, wherein sending the partial channel state information report comprises: An indication of a shift in positioning of a set of coefficients associated with the set of spatial-domain basis functions is sent, wherein the shift in the positioning of the set of coefficients indicates the update to the set of spatial-domain basis functions. The method of claim 7 , wherein the set of coefficients has non-zero values.

9. The method of claim 7, wherein sending the indication of the shift of the positioning of the set of coefficients comprises: A set of bits is sent that indicates a value of an index corresponding to the shift of the positioning of the set of coefficients.

10. The method of claim 7, wherein sending the indication of the shift of the positioning of the set of coefficients comprises: An indication of a set of differential coefficients is sent, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient difference indicates a shift in the value and a shift in the position of the corresponding coefficient in the set of coefficients.

11. The method of claim 1 , wherein sending the complete channel state information report and the partial channel state information report comprises: The complete channel state information report is sent at a first time instance and the partial channel state information report is sent at a second time instance after the first time instance, wherein the second time instance is based at least in part on prediction performed at the UE.

12. The method of claim 11, wherein the prediction is based at least in part on a channel state information measurement rate configured at the UE, a channel state information reporting rate configured at the UE, or both.

13. The method of claim 1, wherein sending the partial channel state information report comprises: receiving, from the network entity, a third message indicating a plurality of sets of coefficients, wherein each set of coefficients in the indicated plurality of sets of coefficients corresponds to a respective set of spatial domain basis functions; as well as An indication of one or more coefficient sets of the indicated plurality of coefficient sets is sent to the network entity based at least in part on the received third message, wherein the one or more coefficient sets indicate the update to the set of spatial domain basis functions.

14. The method of claim 13, wherein sending the indication of the one or more sets of coefficients comprises: An indication of a set of differential coefficients is sent, wherein each differential coefficient in the set of differential coefficients indicates a coefficient difference between a coefficient in a first set of coefficients in the indicated plurality of sets of coefficients and a corresponding coefficient in a second set of coefficients in the indicated plurality of sets of coefficients.

15. A method for wireless communication at a network entity, the method comprising: outputting a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; obtaining, based at least in part on the indicated configuration, a complete channel state information report and a partial channel state information report, the complete channel state information report indicating at least a set of spatial domain basis functions, and the partial channel state information report indicating an update of the set of spatial domain basis functions relative to the complete channel state information report or a previous partial channel state information report; as well as A second message is output based at least in part on the partial channel state information report.

16. The method according to claim 15, further comprising: Outputting a third message instructing a user equipment (UE) to report the update to the set of spatial domain basis functions, wherein obtaining the partial channel state information report is based at least in part on outputting the third message.

17. The method of claim 15, wherein outputting the first message comprises: Outputting an indication of reporting the update of the set of spatial domain basis functions relative to the complete channel state information report or the previous partial channel state information report to a user equipment (UE), wherein obtaining the partial channel state information report indicating the update is based at least in part on outputting the indication.

18. The method according to claim 15, further comprising: A third message including a request to report the update of the set of spatial domain basis functions is obtained from a user equipment (UE), wherein obtaining the partial channel state information report is based at least in part on outputting the third message.

19. The method of claim 15, wherein obtaining the partial channel state information report comprises: An indication of a set of offsets to be applied to the set of spatial-domain basis functions is obtained, wherein each offset in the set of offsets corresponds to a respective spatial-domain basis function in the set of spatial-domain basis functions, and wherein the set of offsets indicates the update to the set of spatial-domain basis functions.

20. The method of claim 19, wherein each offset in the set of offsets identifies a first value corresponding to an azimuth angle associated with the corresponding space-domain basis function and a second value corresponding to a zenith angle associated with the corresponding space-domain basis function.

21. The method of claim 15, wherein obtaining the partial channel state information report comprises: An indication of a shift in positioning of a set of coefficients associated with the set of spatial-domain basis functions is obtained, wherein the shift in the positioning of the set of coefficients indicates the update to the set of spatial-domain basis functions.

22. The method of claim 21, wherein the set of coefficients has non-zero values.

23. The method of claim 21 , wherein obtaining the indication of the shift of the positioning of the set of coefficients comprises: A set of bits is obtained that indicates a value of an index corresponding to the shift of the positioning of the set of coefficients.

24. The method of claim 21 , wherein obtaining the indication of the shift of the positioning of the set of coefficients comprises: An indication of a set of differential coefficients is obtained, wherein each differential coefficient in the set of differential coefficients corresponds to a coefficient difference relative to a corresponding coefficient in the set of coefficients, and wherein the coefficient difference indicates a shift in the value and a shift in the position of the corresponding coefficient in the set of coefficients.

25. The method of claim 15, wherein obtaining the complete channel state information report and the partial channel state information report comprises: The complete channel state information report is obtained at a first time instance and the partial channel state information report is obtained at a second time instance after the first time instance, wherein the second time instance is based at least in part on the first time instance and a prediction performed at a user equipment (UE).

26. The method of claim 25, wherein the prediction is based at least in part on a channel state information measurement rate configured at the UE, a channel state information reporting rate configured at the UE, or both.

27. The method of claim 15, wherein obtaining the partial channel state information report comprises: outputting a third message indicating a plurality of coefficient sets, wherein each coefficient set in the indicated plurality of coefficient sets corresponds to a respective set of spatial domain basis functions; as well as An indication of one or more sets of coefficients of the indicated plurality of sets of coefficients is obtained based at least in part on outputting the third message, wherein the one or more sets of coefficients indicate the update to the set of spatial domain basis functions.

28. The method of claim 27, wherein obtaining the indication of the one or more sets of coefficients comprises: An indication of a set of differential coefficients is obtained, wherein each differential coefficient in the set of differential coefficients indicates a coefficient difference between a coefficient in a first set of coefficients in the indicated plurality of sets of coefficients and a corresponding coefficient in a second set of coefficients in the indicated plurality of sets of coefficients.

29. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receiving, from a network entity, a first message indicating a configuration for reporting spatial domain basis function updates to the network entity; sending, based at least in part on the indicated configuration, a complete channel state information report and a partial channel state information report to the network entity, the complete channel state information report indicating at least a set of spatial domain basis functions and the partial channel state information report indicating an update of the set of spatial domain basis functions relative to the complete channel state information report or a previous partial channel state information report; as well as A second message is received from the network entity based at least in part on the partial channel state information report.

30. An apparatus for wireless communication at a network entity, the apparatus comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: outputting a first message indicating a configuration for reporting a spatial domain basis function update to the network entity; obtaining, based at least in part on the indicated configuration, a complete channel state information report and a partial channel state information report, the complete channel state information report indicating at least a set of spatial domain basis functions, and the partial channel state information report indicating an update of the set of spatial domain basis functions relative to the complete channel state information report or a previous partial channel state information report; as well as A second message is output based at least in part on the partial channel state information report.

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