WO2025081443A1

WO2025081443A1 - Codebook subset restriction indication payload reduction

Info

Publication number: WO2025081443A1
Application number: PCT/CN2023/125533
Authority: WO
Inventors: Liangming WU; Jing Dai
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2025-04-24
Anticipated expiration: 2026-04-20

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a first control message from a network entity that indicates one or more reference signal resources. The UE may receive a second control message that indicates a channel report configuration associated with the one or more reference signal resources. The channel report configuration may include an indication of at least one codebook and a codebook subset restriction (CBSR) indication associated with a channel report. The CBSR indication may include a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The UE may transmit, based on the one or more reference signal resources, the channel report. The channel report may include one or more precoding matrix indicators (PMIs) based on the CBSR indication.

Description

CODEBOOK SUBSET RESTRICTION INDICATION PAYLOAD REDUCTION

FIELD OF TECHNOLOGY

The following relates to wireless communications, including codebook subset restriction (CBSR) indication payload reduction.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the 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, LTE-Advanced (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 technologies 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) . A wireless multiple-access communications system may include one or more base stations, each supporting wireless communication for communication devices, which may be known as user equipment (UE) .

A UE may receive, from a network entity, a configuration of channel state information-reference signal (CSI-RS) resources and a configuration of a CSI report. The UE may receive one or more CSI-RSs via the configured CSI-RS resources and perform channel estimation. The UE may transmit the CSI report based on the channel estimation.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support codebook subset restriction (CBSR) indication payload reduction. For example, the described techniques provide for applying a payload reduction scheme to reduce a size of a CBSR indication. A network entity may indicate reference signal resources and a channel report configuration to a user equipment (UE) . The channel report configuration may include an indication of a codebook and the CBSR indication reduced in size according to the payload reduction scheme. For example, the CBSR indication may include a quantity of bits less than a quantity of entries in the codebook. The UE may select one or more precoding matrix indicators (PMIs) based on the CBSR indication. For example, the CBSR indication may include one or more precoders unavailable for performing communications between the UE and the network entity. The UE may transmit a channel report, based on the channel report configuration, indicating the one or more selected PMIs.

A method for wireless communications by a UE is described. The method may include receiving a first control message that indicates one or more reference signal resources, receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively operable to execute the code to cause the UE to receive a first control message that indicates one or more reference signal resources, receive a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and transmit, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

Another UE for wireless communications is described. The UE may include means for receiving a first control message that indicates one or more reference signal resources, means for receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and means for transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by a processor to receive a first control message that indicates one or more reference signal resources, receive a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and transmit, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the second control message may include operations, features, means, or instructions for receiving, via the second control message, the CBSR indication including a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, where the one or more PMIs included in the channel report may be based on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the second control message may include operations, features, means, or instructions for receiving, via the second control message, the CBSR indication including indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that may be unavailable for selection by the UE, where the one or more PMIs included in the channel report may be different than the precoding matrices indicated by the at least one range of bits in the bitmap.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the indexes may include operations, features, means, or instructions for receiving a first index that points to a first bit in the bitmap and receiving a second index that points to a second bit in the bitmap, where the at least one range of bits includes the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the second control message may include operations, features, means, or instructions for receiving, via the second control message, the CBSR indication including the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, where a respective quantity of precoders in each of the first dimension and the second dimension may be less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based on a down sampling factor in accordance with the payload reduction scheme, and where the one or more PMIs included in the channel report may be based on values of the first quantity of bits in the CBSR indication.

Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a third control message that indicates the down sampling factor.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the set of precoders may be associated with a first quantity of antenna elements along the first dimension of an antenna panel and a second quantity of antenna elements along the second dimension of the antenna panel.

Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook may be mapped to the CBSR indication and selecting the one or more PMIs to include in the channel report based on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for calculating, based on a translation ratio, an adjusted value for a respective index of each entry of the second quantity of entries in the at least one codebook, where the translation ratio may be based on a ratio of the first size of the CBSR indication and the second size of the at least one codebook and selecting, for each entry of the second quantity of entries, an index in the CBSR indication that may be closest to the adjusted value for the respective index of the entry, where the translation of the first size of the CBSR indication to the second size of the at least one codebook may be based on the selecting.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the translation of the first size of the CBSR indication to the second size of the at least one codebook may be based on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the CBSR indication that may have a first value.

Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving one or more reference signals via the one or more reference signal resources, performing a channel estimation based on measurements of the one or more reference signals, and selecting the one or more PMIs to include in the channel report based on the channel estimation and the CBSR indication.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the second quantity of entries in the at least one codebook may be based on a quantity of antenna elements used for communications with the UE.

In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the first control message, the second control message, or both include radio resource control (RRC) messages.

A method for wireless communications by a network entity is described. The method may include transmitting a first control message that indicates one or more reference signal resources, transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

A network entity for wireless communications is described. The network entity may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively operable to execute the code to cause the network entity to transmit a first control message that indicates one or more reference signal resources, transmit a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and receive, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

Another network entity for wireless communications is described. The network entity may include means for transmitting a first control message that indicates one or more reference signal resources, means for transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and means for receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by a processor to transmit a first control message that indicates one or more reference signal resources, transmit a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme, and receive, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, transmitting the second control message may include operations, features, means, or instructions for transmitting, via the second control message, the CBSR indication including a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, where the one or more PMIs included in the channel report may be based on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel at the network entity and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel at the network entity.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, transmitting the second control message may include operations, features, means, or instructions for transmitting, via the second control message, the CBSR indication including indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that may be unavailable for inclusion in the channel report, where the one or more PMIs included in the channel report may be different than the precoding matrices indicated by the at least one range of bits in the bitmap.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, transmitting the indexes may include operations, features, means, or instructions for transmitting a first index that points to a first bit in the bitmap and transmitting a second index that points to a second bit in the bitmap, where the at least one range of bits includes the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, transmitting the second control message may include operations, features, means, or instructions for transmitting, via the second control message, the CBSR indication including the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, where a respective quantity of precoders in each of the first dimension and the second dimension may be less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based on a down sampling factor in accordance with the payload reduction scheme, and where the one or more PMIs included in the channel report may be based on values of the first quantity of bits in the CBSR indication.

Some examples of the method, network entities, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a third control message that indicates the down sampling factor.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the set of precoders may be associated with a first quantity of antenna elements along the first dimension of an antenna panel at the network entity and a second quantity of antenna elements along the second dimension of the antenna panel at the network entity.

Some examples of the method, network entities, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook may be mapped to the CBSR indication, and where the one or more PMIs in the channel report may be based on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the translation of the first size of the CBSR indication to the second size of the at least one codebook may be based on a ratio of the first size of the CBSR indication and the second size of the at least one codebook.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the translation of the first size of the CBSR indication to the second size of the at least one codebook may be based on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the CBSR indication that may have a first value.

Some examples of the method, network entities, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting one or more reference signals via the one or more reference signal resources, where the one or more PMIs in the channel report may be based on the one or more reference signals.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the second quantity of entries in the at least one codebook may be based on a quantity of antenna elements used for communications by the network entity.

In some examples of the method, network entities, and non-transitory computer-readable medium described herein, the first control message, the second control message, or both include RRC messages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless communications system that supports codebook subset restriction (CBSR) indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 2 shows an example of a wireless communications system that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIGs. 3, 4A, and 4B show examples of payload reduction schemes that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIGs. 5A, 5B, and 5C show examples of CBSR mapping schemes that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 6 shows an example of a process flow that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIGs. 7 and 8 show block diagrams of devices that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 9 shows a block diagram of a communications manager that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 10 shows a diagram of a system including a device that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIGs. 11 and 12 show block diagrams of devices that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 13 shows a block diagram of a communications manager that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIG. 14 shows a diagram of a system including a device that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

FIGs. 15 through 18 show flowcharts illustrating methods that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure.

DETAILED DESCRIPTION

A user equipment (UE) may receive, from a network entity, one or more control messages that indicate reference signal resources (e.g., channel state information-reference signal (CSI-RS) resources, or some other type of resources) and that indicate a channel report configuration (e.g., a CSI report configuration) . The UE may estimate a quality of a channel based on the reference signal resources and may indicate the channel quality by transmitting one or more measured parameters via the CSI report. The CSI report may indicate, among other metrics, one or more precoding matrix indicators (PMIs) . A PMI may identify a preferred precoding matrix for the network entity to use for communications with the UE. The network entity may transmit a codebook subset restriction (CBSR) to the UE to assist with the PMI selection by the UE. The CBSR may be a bitmap that includes a bit for each potential precoding matrix, which may correspond to a respective beam produced by an antenna panel at the network entity. A value of each bit may indicate whether the UE may select a corresponding PMI to report via the CSI report. For example, the CBSR may include a quantity of bits that is equal to a product of a quantity of antenna ports, a quantity of oversampling ratios, and a quantity of polarizations used by the network entity, which may be a relatively large quantity of bits. As such, methods to reduce the size of the CBSR payload and overhead may be beneficial.

As described herein, the network entity may reduce the CBSR payload size by applying a payload reduction scheme such that the CBSR may include a quantity of bits less than a quantity of entries in a corresponding codebook. For example, the network entity may transmit two separate CBSR bitmaps each associated with a single dimension. A first bitmap may indicate precoders associated with a first set of antenna elements in a first dimension (e.g., a vertical dimension) , and a second bitmap may indicate precoders and beams associated with a second set of antenna elements in a second dimension (e.g., a horizontal dimension) . A product of the two bitmaps may yield the overall CBSR indication (e.g., a CBSR bitmap) . Additionally, or alternatively, the network entity may transmit indices including one or more ranges of bits in the CBSR that indicate a PMI restriction, or the network entity may reduce the codebook size by a down sampling factor in each dimension.

In some examples, the network entity may configure a set of CBSR configurations (e.g., multiple CBSR configurations) and may indicate an association between CBSR configurations and respective codebook configurations. For example, the network entity and the UE may utilize a translation scheme to translate a CBSR of a first size to apply to one or more different codebooks having different sizes than the CBSR. The network entity described herein may thereby reduce a payload of a CBSR, and may support associations between CBSRs and codebooks of various sizes, which may support reduced overhead, improved reliability, and improved coordination between devices, among other examples.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further described by payload reduction schemes, CBSR mapping schemes, and process flows Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to CBSR indication payload reduction.

FIG. 1 shows an example of a wireless communications system 100 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating in accordance with other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

The network entities 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may include devices in different forms or having different capabilities. In various examples, a network entity 105 may be referred to as a network element, a mobility element, a radio access network (RAN) node, or network equipment, among other nomenclature. In some examples, network entities 105 and UEs 115 may wirelessly communicate via one or more communication links 125 (e.g., a radio frequency (RF) access link) . For example, a network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) over which the UEs 115 and the network entity 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a network entity 105 and a UE 115 may support the communication of signals according to one or more radio access technologies (RATs) .

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of supporting communications with various types of devices, such as other UEs 115 or network entities 105, as shown in FIG. 1.

As described herein, a node of the wireless communications 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, a node may be a UE 115. As another example, a 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 yet other aspects of this example, the first, second, and third nodes may be different relative to these examples. Similarly, reference to a UE 115, network entity 105, apparatus, device, computing system, or the like may include disclosure of the UE 115, network entity 105, apparatus, device, computing system, or the like being a node. For example, disclosure that a UE 115 is configured to receive information from a network entity 105 also discloses that a first node is configured to receive information from a second node.

In some examples, network entities 105 may communicate with the core network 130, or with one another, or both. For example, network entities 105 may communicate with the core network 130 via one or more backhaul communication links 120 (e.g., in accordance with an S1, N2, N3, or other interface protocol) . In some examples, network entities 105 may communicate with one another via a backhaul communication link 120 (e.g., in accordance with an X2, Xn, or other interface protocol) either directly (e.g., directly between network entities 105) or indirectly (e.g., via a core network 130) . In some examples, network entities 105 may communicate with one another via a midhaul communication link 162 (e.g., in accordance with a midhaul interface protocol) or a fronthaul communication link 168 (e.g., in accordance with a fronthaul interface protocol) , or any combination thereof. The backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 may be or include one or more wired links (e.g., an electrical link, an optical fiber link) , one or more wireless links (e.g., a radio link, a wireless optical link) , among other examples or various combinations thereof. A UE 115 may communicate with the core network 130 via a communication link 155.

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 base transceiver station, a radio base station, an NR base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a 5G NB, a next-generation eNB (ng-eNB) , a Home NodeB, a Home eNodeB, or other suitable terminology) . In some examples, a network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture, which may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as a base station 140) .

In some examples, a network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) , which may be configured to utilize a protocol stack that is physically or logically distributed among two or more network entities 105, such as 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) ) . For example, a network entity 105 may include one or more of a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN Intelligent Controller (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) 180 system, or any combination thereof. An 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 transmission reception point (TRP) . One or more components of the network entities 105 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 105 may be located in distributed locations (e.g., separate physical locations) . In some examples, one or more network entities 105 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

The split of functionality between a CU 160, a DU 165, and an RU 170 is flexible and may support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combinations thereof) are performed at a CU 160, a DU 165, or an RU 170. For example, a functional split of a protocol stack may be employed between a CU 160 and a DU 165 such that the CU 160 may support one or more layers of the protocol stack and the DU 165 may support one or more different layers of the protocol stack. In some examples, the CU 160 may host upper protocol layer (e.g., layer 3 (L3) , layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 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 a DU 165 and an 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 multiple different cells (e.g., via one or more RUs 170) . In some cases, a functional split between a CU 160 and a DU 165, or between a DU 165 and an RU 170 may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU 160, a DU 165, or an RU 170, while other functions of the protocol layer are performed by a different one of the CU 160, the DU 165, or the RU 170) . A CU 160 may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU 160 may be connected to one or more DUs 165 via a midhaul communication link 162 (e.g., F1, F1-c, F1-u) , and a DU 165 may be connected to one or more RUs 170 via a fronthaul communication link 168 (e.g., open fronthaul (FH) interface) . In some examples, a midhaul communication link 162 or a fronthaul communication link 168 may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 105 that are in communication via such communication links.

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

In the case of the techniques described herein applied in the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support CBSR indication payload reduction 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 disaggregated RAN architecture (e.g., IAB nodes 104, DUs 165, CUs 160, RUs 170, RIC 175, SMO 180) .

A 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 terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A 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, a UE 115 may include or 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 communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the network entities 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the network entities 105 may wirelessly communicate with one another via one or more communication links 125 (e.g., an access link) using resources associated with one or more carriers. The term “carrier” may refer to a set of RF spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a RF spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for 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 that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. Communication between a network entity 105 and other devices may refer to communication between the devices and any portion (e.g., entity, sub-entity) of a network entity 105. For example, the terms “transmitting, ” “receiving, ” or “communicating, ” when referring to a network entity 105, may refer to any portion of a network entity 105 (e.g., a base station 140, a CU 160, a DU 165, a RU 170) of a RAN communicating with another device (e.g., directly or via one or more other network entities 105) .

Signal waveforms transmitted via a carrier may be made up of 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 employing MCM techniques, a resource element may refer to resources of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The quantity 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) , such that a relatively higher quantity of resource elements (e.g., in a transmission duration) and a relatively higher order of a modulation scheme may correspond to a relatively higher rate of communication. A wireless communications resource may refer to a combination of an RF spectrum resource, a time resource, and a spatial resource (e.g., a spatial layer, a beam) , and the use of multiple spatial resources may increase the data rate or data integrity for communications with a UE 115.

The time intervals for the network entities 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T_s=1/ (Δf_max·N_f) seconds, for which Δf_max may represent a supported subcarrier spacing, and N_f may represent a supported discrete Fourier transform (DFT) size. Time intervals of a communications resource 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) .

Each frame may include multiple consecutively-numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a quantity of slots. Alternatively, each frame may include a variable quantity of slots, and the quantity of slots may depend on subcarrier spacing. Each slot may include a quantity of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems 100, a slot may further be divided into multiple mini-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) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., a quantity of symbol periods in a TTI) may be variable. Additionally, or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .

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

A network entity 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a network entity 105 (e.g., using a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) , or others) . In some examples, a cell also may refer to a coverage area 110 or a portion of a coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the network entity 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with coverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered network entity 105 (e.g., a lower-powered base station 140) , as compared with a macro cell, and a small cell may operate using the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A network entity 105 may support one or multiple cells and may also support communications via the one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.

In some examples, a network entity 105 (e.g., a base station 140, an RU 170) may be movable and therefore provide communication coverage for a moving coverage area 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, the overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the network entities 105 provide coverage for various coverage areas 110 using the same or different radio access technologies. The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) . The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications 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 general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein.

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

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 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the network entities 105 (e.g., base stations 140) associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services 150 for one or more network operators. The IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

The wireless communications system 100 may operate using one or more frequency bands, which may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, which may be referred to as clusters, but the waves may penetrate structures sufficiently for a macro cell to provide service to the 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 the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may utilize both licensed and unlicensed RF spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology using an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. While operating using unlicensed RF spectrum bands, devices such as the network entities 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations using unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating using a licensed band (e.g., LAA) . Operations using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A network entity 105 (e.g., a base station 140, an RU 170) or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a network entity 105 or a UE 115 may be located within 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 a network entity 105 may be located at diverse geographic locations. A network entity 105 may include an antenna array with a set of rows and columns of antenna ports that the network entity 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally, or alternatively, an antenna panel may support RF beamforming for a signal transmitted via an antenna port.

The network entities 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the 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 used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) , for which multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , for which multiple spatial layers are transmitted to multiple devices.

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 steer 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 the signals communicated via antenna elements of an antenna array such that some signals propagating along particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

A network entity 105 or a UE 115 may use beam sweeping techniques as part of beamforming operations. For example, a network entity 105 (e.g., a base station 140, an RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a network entity 105 multiple times along different directions. For example, the network entity 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as a network entity 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the network entity 105.

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

In some examples, transmissions by a device (e.g., by a network entity 105 or a 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 a network entity 105 to a UE 115) . The UE 115 may report feedback that indicates 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 sub-bands. The network entity 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a PMI (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted along one or more directions by a network entity 105 (e.g., a base station 140, an RU 170) , a UE 115 may employ similar techniques for transmitting signals multiple times along different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal along a single direction (e.g., for transmitting data to a receiving device) .

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

A UE 115 in the wireless communications system 100 may receive reference signals from a network entity 105 and may measure channel metrics associated with the reference signals. The UE 115 may transmit a channel report (e.g., a CSI report) with the measured metrics. The channel report may indicate, among other metrics, one or more PMIs that identify a preferred precoding matrix for the network entity 105 to use for communications with the UE 115. In some examples, the network entity 105 may transmit a CBSR indication to the UE 115. The CBSR indication may include one or more precoders which are unavailable for selection by the UE 115 to include in a PMI within a channel report (e.g., a CSI report) . The CBSR indication may define the one or more precoders which are unavailable for selection via a bitmap. For example, the bitmap may include a quantity of bits corresponding to a respective beam generated by an antenna element of an antenna panel of the network entity 105. Bits having a zero value may indicate to the UE 115 that the beam corresponding to the bit is unavailable.

As described herein, the network entity 105 may reduce a size of a CBSR indication according to a payload reduction scheme. For example, the network entity 105 may reduce the size of the CBSR indication such that a quantity of bits of the CBSR may be less than a quantity of bits of a codebook. The payload reduction scheme may include transmitting the CBSR indication via two bitmaps (e.g., two one-dimensional bitmaps, where a product of the two bitmaps may yield the CBSR bitmap) , via an indication of one or more ranges of bits of the bitmap, via a down sampling factor applied to one or more dimensions, or any combination thereof.

The UE 115 may receive one or more CBSR indications having the reduced size. In some examples, the UE 115 may map a set of codebooks to the one or more CBSR indications. For example, the UE 115 may translate a CBSR of a first size to apply to one or more codebooks (e.g., different codebooks) having different sizes than the CBSR. Techniques for CBSR indications and CBSR-to-codebook associations are described in further detail elsewhere herein, including with reference to FIGs. 2–6.

FIG. 2 shows an example of a wireless communications system 200 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The wireless communications system 200 may implement or be implemented by aspects of the wireless communications system 100. For example, the wireless communications system 200 may include a network entity 105 associated with a coverage area 110 including a UE 115, which may represent examples of a network entity 105, a coverage area 110, and a UE 115 as described with reference to FIG. 1.

The network entity 105 may be associated with (e.g., include, be deployed with, or be coupled with) an antenna panel 205. Although not shown, the UE 115 may also include an antenna array. The network entity 105 may communicate with the UE 115 and one or more other devices via the antenna panel 205.

The network entity 105 may support MIMO communications using the antenna panel 205. The antenna panel 205 may include multiple antenna ports 210, which may be referred to as antenna arrays, antenna elements, antenna components, or antennas. In some aspects, a quantity of antenna ports 210 in the antenna panel 205 may be relatively high, and the MIMO communications may be referred to as massive MIMO (mMIMO) . Antenna ports or elements within a same antenna panel 205 may be associated with a relatively high correlation. However, the antenna panel 205 may support at least two degrees or polarizations of channels. For example, the antennas of the antenna panel 205 may be polarized in at least a vertical direction and a horizontal direction. A wireless channel associated with a first polarization may be independent (e.g., separate) from a wireless channel associated with a second polarization.

The antenna ports 210 as described herein may refer to polarization-specific antenna ports 210. For example, a same physical antenna panel or array may include two or more antenna ports 210 each associated with a respective polarization. In the example of FIG. 2, the solid diagonal lines in the antenna panel 205 may represent antenna ports 210-a associated with a first polarization and the dashed diagonal lines in the antenna panel 205 may represent antenna ports 210-b associated with a second polarization. The antenna ports 210 may correspond to respective beams. For example, the network entity 105 may generate multiple beams via the antenna ports 210 to communicate signals with the UE 115. In some examples, the UE 115 may, via channel reporting, indicate one or more preferred beams associated with antenna ports 210 of the network entity 105. For example, the UE 115 may indicate a preference to use a respective beam, and the network entity 105 may communicate with the UE 115 with the respective beam according to the indicated preference.

The UE 115 may report channel information (e.g., CSI) to the network entity 105 (e.g., periodically or aperiodically) . For example, the UE 115 may receive a control message 215 from the network entity 105 indicating reference signal resources (e.g., CSI-RS resources) and a channel report configuration 220 (e.g., a CSI report configuration, or some other type of channel report configuration) . The network entity 105 may transmit reference signals 225 (e.g., CSI-RSs, or some other type of reference signal) to the UE 115 via the indicated reference signal resources. For example, the UE 115 may monitor the indicated reference signal resources and measure parameters associated with the received reference signals 225. In some examples, the UE 115 may measure the parameters according to the channel report configuration 220. For example, the channel report configuration 220 may indicate the one or more parameters to be measured (and reported) by the UE 115. In other words, the UE 115 may perform channel estimation based on the reference signals 225.

The UE 115 may transmit a channel report 230 (e.g., a CSI report) to the network entity 105 based on performing the channel estimation and according to the channel report configuration 220. The channel report 230 may include a channel quality indicator (CQI) 235, a precoding matrix indicator (PMI) 240, a rank indicator (RI) 245, one or more other parameters, or any combination thereof.

The channel report 230 may include one or more PMIs 240, where each PMI 240 may indicate a preferred or suggested precoding matrix for the network entity 105 to use for communications with the UE 115. That is, the network entity 105 may use the precoding matrix to precode downlink signals to be transmitted to the UE 115. In some examples, the network entity 105 may indicate a set of precoding matrices to be considered by the UE 115. For example, the network entity 105 may indicate the set of precoding matrices from which the UE 115 may select the preferred or selected precoding matrix via the channel report configuration 220. The set of precoding matrices may be referred to as a codebook. In some cases, the network entity 105 may indicate multiple sets of precoding matrices (e.g., multiple codebooks) to the UE 115 via the channel report configuration 220.

In some examples, the network entity 105 may indicate one or more CBSR indications (e.g., a CBSR indication corresponding to each codebook) in the channel report configuration 220. For example, the network entity 105 may include one or more CBSR indications in the channel report configuration 220. A CBSR may indicate a set of one or more precoders that is unavailable for selection by the UE 115. For example, if a precoder is indicated via the CBSR (e.g., via a bit set to a certain value in the CBSR, or some other indication) , the UE 115 may remove that precoder from a pool of candidate precoders from which the UE 115 may select a preferred or suggested precoding matrix. The network entity 105 may transmit a CBSR indication to indicate one or more precoders as unavailable when, for example, the network entity 105 performs a beamforming operation in a given direction (e.g., is restricted to a certain direction) . For example, the network entity 105 may indicate the one or more precoders as unavailable based on interference to neighboring TRPs, self-interference, or the like.

The network entity 105 may indicate the CBSR via a bitmap in which each bit of the bitmap corresponds to a respective beam generated by an antenna element of the antenna panel 205. For example, the bitmap may include a quantity of bits that is equal to a product of a quantity of antenna elements in the antenna panel 205, a quantity of one or more oversampling ratios associated with respective dimensions of the antenna panel 205, and a quantity of polarizations supported by the antenna panel 205. That is, the quantity of bits in the bitmap may be a product of a quantity of antenna elements in a horizontal dimension, N₁, a quantity of antenna elements in a vertical dimension, N₂, an oversampling ratio in the horizontal dimension, O₁, an oversampling ratio in the vertical dimension, O₂, and a quantity of polarizations (e.g., two in this example) . A quantity of bits may be defined as, and interchangeably referred to as, a bit length. In one example, if the antenna panel 205 includes 128 antenna elements and the network entity 105 supports 16 oversampling ratios (e.g., O₁O₂=16) and two polarizations, then the corresponding CBSR bitmap may include 1024 bits.

The network entity 105 may set one or more bits of the bitmap to zero. A bit that is set to zero (e.g., or some other value) may indicate that the UE 115 may not select a precoding matrix corresponding to the bit as the preferred or suggested precoding matrix. For example, each bit position in the bitmap may be associated with a corresponding entry in the codebook, such as a corresponding precoding matrix. If a bit in bit position three, for example, is set to zero, a precoding matrix associated with entry three in the corresponding codebook may be removed from a candidate pool. As such, a size of a payload for the CBSR indication (e.g., the bitmap size) may increase as a size of the antenna panel 205, a quantity of codebooks configured by the network entity 105, and a quantity of port configurations increase.

Techniques, systems, and devices described herein provide for the network entity 105 to reduce the payload size of the CBSR indication according to a payload reduction scheme. The network entity 105 may reduce the quantity of bits of the CBSR indication such that the size of the CBSR indication may be less than a size of a corresponding codebook. In some aspects, the reduction to the CBSR indication may reduce overhead associated with channel reporting between the network entity 105 and the UE 115.

The payload reduction scheme may include a decoupling of the bitmap (described in further detail elsewhere herein, including with reference to FIG. 3) , an indication of one or more ranges of bits (described in further detail elsewhere herein, including with reference to FIG. 4A) , a resolution reduction according to a down sampling factor (described in further detail elsewhere herein, including with reference to FIG. 4B) , or any combination thereof. That is, the network entity 105 may reduce the size of the payload according to one or multiple payload reduction schemes.

Additionally, or alternatively, the network entity 105 may indicate, via the channel report configuration 220 or in a separate control message, an association between one or more CBSR configurations and one or more codebook configurations. For example, the UE 115 may map a codebook configuration to a CBSR configuration of a different size than the codebook based on the translation indicated by the network entity 105. The mapping of codebook configurations to CBSR configurations is described in further detail elsewhere herein, including with reference to FIGs. 5A, 5B, and 5C.

FIG. 3 shows an example of a payload reduction scheme 300 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The payload reduction scheme 300 may implement or be implemented by aspects of the wireless communications system 100, the wireless communications system 200, or both. For example, the payload reduction scheme 300 may be implemented by a network entity 105 as described with reference to FIGs. 1 and 2.

As described herein, to reduce a payload of a CBSR indication, the network entity may transmit the CBSR indication to a UE as two one-dimensional bitmaps. For example, the network entity may transmit the CBSR indication as the two bitmaps, where a product of the two bitmaps is indicative of the CBSR bitmap. The UE receiving the CBSR indication as the two bitmaps may generate the CBSR bitmap (e.g., the full bitmap) based on a product of the two bitmaps. The two bitmaps and the CBSR bitmap may include one or more restricted bits 305. That is, each bitmap may include the one or more restricted bits 305, where the restricted bits 305 indicate that a precoding matrix is unavailable for selection by the UE (e.g., the restricted bits 305 are bits set to zero) .

A first bitmap 310-a may include a quantity of bits A₁, which may be equal to a product of a quantity of antenna elements in a horizontal dimension, N₁, and an oversampling ratio in the horizontal dimension, O₁ (e.g., A₁=N₁O₁) . A second bitmap 310-b may include a quantity of bits A₂, which may be equal to a product of a quantity of antenna elements in a vertical dimension, N₂, and an oversampling ratio in the vertical dimension, O₂ (e.g., A₂=N₂O₂) . The first bitmap 310-a may thereby be a horizontal vector and the second bitmap 310-b may be a vertical vector (e.g., each one-dimensional vectors) .

A UE, or, generally, a device receiving the first bitmap 310-a and the second bitmap 310-b, may generate (e.g., construct, estimate, calculate, determine, produce, etc. ) a two-dimensional bitmap 310-c. Each bit of the quantity of bits in the two-dimensional bitmap 310-c may represent a respective precoder of the corresponding codebook. The UE may generate the two-dimensional bitmap 310-c according to a product of the first bitmap 310-a and the second bitmap 310-b, or, in other words, according to Equation 1, where the two-dimensional bitmap 315, c, is the product of the first bitmap 310-a, a, and the second bitmap 310-b, b.

The quantity of bits (e.g., length) of the two-dimensional bitmap 315 is defined as A_c and is calculated according to Equation 2.
A_c=N₁O₁N₂O₂ (2)

The network entity may indicate the first bitmap 310-a and the second bitmap 310-b to the UE via a first bitmap parameter n₁ and a second bitmap parameter n₂.The first bitmap parameter and the second bitmap parameter may form respective bit sequencesandwhere a₀, b₀is the least significant bit andis the most significant bit.

In some examples, the two-dimensional bitmap 315 produced via the product of the first bitmap 310-a and the second bitmap 310-b may have a lower granularity level than, for example, a CBSR indication having a full payload (e.g., not reduced according to a reduction scheme) . The two-dimensional bitmap 315 provided via the product may include one or more restricted bits 305 (e.g., bits set to zero) which are unnecessarily restricted, or may include one or more unrestricted bits that the network entity intended to restrict.

For example, the network entity may transmit the first bitmap 310-a and the second bitmap 310-b to reduce the payload size of the CBSR indication, but the generated two-dimensional bitmap 310-c may, as a result of calculating the product of the first bitmap 310-a and the second bitmap 310-b, have restricted bits 305 which the network entity would not have restricted in a CBSR indication having the full payload, or unrestricted bits that the network entity would have restricted in the CBSR indication having the full payload, or both.

In some examples, the bitin the bitmap may be associated with all precoders based on the quantity v_l, _m, l=0, . . ., N₁O₁-1, m=0, . . ., N₂O₂-1, except when the quantity of layers is between a given range (e.g., υ∈ {3, 4} ) and the quantity of antenna ports is a threshold quantity (e.g., 16, 24, or 32) .

Additionally, or alternatively, when the quantity of layers is between the given range and the quantity of antenna ports is the same as the threshold quantity, bits andmay each be associated with all precoders based on the quantity When one or more of the associated bits is set to zero, then PMI reporting may not be allowed to correspond to any precoder based on

A network entity may thereby reduce a size of a CBSR payload by dividing a codebook into two dimensions and transmitting an indication of two one-dimensional bitmaps to a UE 115 via the CBSR indication. The UE 115 may calculate a product of the two one-dimensional bitmaps to identify corresponding precoders that are restricted.

FIG. 4A and FIG. 4B each show an example of payload reduction schemes 400-a and 400-b that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The payload reduction schemes 400-a and 400-b may implement or be implemented by aspects of the wireless communications system 100, the wireless communications system 200, or both. For example, the payload reduction schemes 400-a and 400-b may be implemented by a network entity 105 as described with reference to FIGs. 1 and 2.

In the example of FIG. 4A, to reduce a payload of a CBSR indication, the network entity may transmit a CBSR indication as one or more ranges. For example, the one or more ranges may correspond to locations in a bitmap that correspond to (e.g., indicate) respective precoders that are unavailable for selection by a UE (e.g., bits set to zero) . In other words, the bitmap includes bits representative of precoders in a codebook, and the one or more ranges may point to pairs of starting and ending bits in the bitmap (e.g., such that a consecutive range between the starting and ending bits is defined) .

The CBSR indication may include one or more ranges denoted by a starting point 410 and an ending point 415, where bits within each range (e.g., between the starting point 410 and the ending point 415) are restricted bits 305. For example, the CBSR indication may indicate a start point 410-a paired with an end point 415-a, a start point 410-b paired with an end point 415-b, or any combination thereof. The CBSR indication, in such cases, may be referred to as a range-based bitmap.

The start points 410 and the end points 415 may reference a precoder of a codebook corresponding to (e.g., being referenced by and/or associated with) the CBSR indication. For example, the start point 410-a may reference (e.g., point to) a first precoder of the codebook, and the end point 415-a may reference a second precoder of the codebook. The precoders in between the first precoder and the second precoder, according to the CBSR indication including the range, would be unavailable for selection by the UE receiving the CBSR indication (e.g., unavailable to select as a preferred PMI) .

The start points 410 and end points 415 may be indicated via a set of bits. For example, the network entity may convey a set of bits set to a certain value to indicate or point to a corresponding precoder. A quantity of bits that are used for the indication of each point or precoder may be defined according to Equation 3, where w represents the quantity of bits in the indication (e.g., a bit width) .
w=log₂N₁O₁ (3)

That is, each of the start points 410-a and 410-b, as well as each of the end points 415-a and 415-b, may be indicated via a quantity of bits that is equal to w. If a quantity of bits of a bitmap that represents precoders (e.g., N₁O₁) , is 256, the CBSR indication may use eight bits to indicate a starting point 410 in the bitmap and eight bits to indicate an ending point 415 in the bit map, such that 16 total bits may be used to indicate a range of restricted bits 305. The network entity may thereby utilize fewer bits by indicating the range-based CBSR than if the network entity indicates a full CBSR bitmap (e.g., a full CBSR bitmap, a CBSR table, etc. ) .

In some examples, the range-based bitmap may be indicated in conjunction with the indication of the two bitmaps as described with reference to FIG. 3. For example, the ranges of bits may point to ranges of bits in either of two one-dimensional (e.g., either horizontal or vertical) bitmaps. In other words, the range-based bitmap may be used to indicate which of the bits of the first bitmap and the second bitmap are restricted bits 305 (e.g., set to zero) .

The range-based bitmap may be associated with reduced overhead at the network entity, the UE, or both as opposed to a full bitmap. In some examples, the range-based bitmap may be understood as a compression of a CBSR table (e.g., a full CBSR table) . In some examples, the network entity may indicate no more than a threshold quantity of ranges via the CBSR indication. The threshold quantity may be defined (e.g., at the network entity, in a standard, or the like) , or indicated via signaling, or both. The threshold quantity may be a quantity of ranges such that an overhead associated with communicating the payload of the CBSR indication is reduced (e.g., as opposed to a two-dimensional bitmap) .

In the example of FIG. 4B, to reduce overhead associated with the CBSR indication, the network entity may transmit the CBSR indication with a reduced resolution. For example, the network entity may transmit a bitmap having one or more dimensions reduced according to a down sampling factor. Before the reduction, the bitmap 420 (e.g., the full, unreduced bitmap) may include bits representative of precoders in a codebook. A quantity of bits in the initial bitmap 420 may be equal to a quantity of precoders. For example, the bitmap 420 may be a two-dimensional bitmap that includes a quantity of bits equal to N₁O₁N₂O₂, with N₁O₁ in a first (e.g., horizontal dimension) and N₂O₂ bits in a second (e.g., vertical) dimension.

To reduce a size of the CBSR payload, the network entity may apply a resolution reduction to a horizontal dimension of a CBSR bitmap, a vertical dimension of the CBSR bitmap, or both to obtain the bitmap 425. The network entity may indicate the resulting bitmap 425 via the CBSR indication, which may be associated with reduced resolution and may be smaller in size than the bitmap 420. The resolution reduction may include applying a down sampling factor (e.g., X) to the horizontal dimension, the vertical dimension, or both. In other words, the network entity may divide a quantity of bits in the horizontal dimension, a quantity of bits in the vertical dimension, or both by the down sampling factor. In some examples, the network entity may apply a first down sampling factor, X₁, in the horizontal dimension and a second down sampling factor, X₂, in the vertical dimension. That is, the down sampling factors applied to the vertical and horizontal dimensions may be the same or different.

The down sampling factor may be indicated via signaling (e.g., via RRC signaling, or some other type of signaling) or may be configured (e.g., defined at the devices, in a standard, or the like) . In the example of FIG. 4B, the down sampling factor may be two. However, it is to be understood that the down sampling factor may be any numerical value.

For example, with reference to FIG. 4B, the network entity may divide the quantity of bits of the horizontal dimension, N₁O₁, by the down sampling factor to produce a reduced quantity of bitsAdditionally, or alternatively, the network entity may divide the quantity of bits of the vertical dimension N₂O₂, by the down sampling factor to produce a reducedAlthough resolution reduction in both dimensions is illustrated in FIG. 4B, it is to be understood that, in some examples, the resolution reduction may be applied to a single dimension.

The CBSR indication including the bitmap 425 with the reduced resolution may be associated with a reduced overhead compared to a CBSR indication with the full (e.g., non-reduced) bitmap 425. For example, the application of the down sampling factor to one of the dimensions of the bitmap may reduce the overhead by a factor equal to the down sampling factor, and the application of the down sampling factor to both of the dimensions of the bitmap may reduce the overhead exponentially. That is, if the down sampling factor is two, and the down sampling factor is applied to both dimensions of the bitmap, the overhead may be reduced by a factor of four.

The UE may receive an indication of the down sampling factor from the network entity. Additionally, or alternatively, the down sampling factor may be predefined (e.g., known to the UE without signaling) . In some examples, the UE may determine (e.g., implicitly) the down sampling factor based on the size of the CBSR configuration (e.g., the CBSR indication, the CBSR bitmap, etc. ) . For example, the UE may determine the down sampling factor for the horizontal dimension, the vertical dimension, or both according to Equation 4, where N′O′ are defined as a size (e.g., a size of the vertical or horizontal dimension) of the CBSR configuration.
X=NO/N′O′ (4)

The UE may apply the down sampling factor to the reduced bitmap 425 to translate the indicated restricted bits 305 to corresponding bits in the full bitmap 420. In other words, the UE may multiply each dimension of the reduced bitmap 425 by the down sampling factor to produce the full bitmap 420, where the full bitmap 420 includes bits corresponding to the precoders of the codebook. The UE may refrain from selecting any precoders that are associated with restricted bits 305.

FIGs. 5A, 5B, and 5C show examples of CBSR mapping schemes 500-a, 500-b, and 500-c that support CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The CBSR mapping schemes 500-a, 500-b, and 500-c may implement or be implemented by aspects of the wireless communications system 100, the wireless communications system 200, or both. For example, the CBSR mapping schemes 500-a, 500-b, and 500-c may be implemented by a UE 115 as described with reference to FIGs. 1 and 2.

A network entity may indicate a translation between one or more CBSR configurations and one or more codebook configurations. For example, the UE may map one or more codebook configurations to respective CBSR configurations according to the translation indicated by the network entity. The translation between the one or more CBSR configurations may be indicated via a same control message as the CBSR indication, the codebook configurations, or both, or via a different control message.

In some examples, the UE may use the CBSR mapping schemes 500-a, 500-b, and 500-c based on a quantity of beams represented in a codebook configuration being different than a quantity of beams represented in a CBSR configuration. In other words, the UE may use the CBSR mapping schemes to translate entries of a CBSR table to entries of a codebook configuration. The UE may use the CBSR mapping schemes to identify which precoders of the codebook configurations are unavailable for selection (e.g., denoted by restricted bits 305) .

In some examples, the UE may use the CBSR mapping schemes to map one-dimensional vectors (e.g., such as the two bitmaps discussed with reference to FIG. 3) . For example, the CBSR mapping schemes 500-b and 500-c are illustrated in the context of mapping one-dimensional vectors. However, the CBSR mapping schemes 500-b and 500-c may also be applied to CBSR tables (e.g., CBSR configurations, CBSR bitmaps, etc. ) , codebook configurations, or the like having two or more dimensions.

In the example of FIG. 5A, the UE may receive control signaling indicative of a codebook configuration 505-a, a codebook configuration 505-b, and a codebook configuration 505-c. Additionally, or alternatively, the UE may receive control signaling indicative of a CBSR configuration 510-a and a CBSR configuration 510-b. The control signaling may be an RRC message (e.g., same RRC messages or different RRC messages) .

The UE may receive an indication of the translation between the codebook configurations 505 and the CBSR configurations 510, and the UE may map respective codebook configurations to CBSR configurations according to the indicated translation. The indication of the translation may include a set of rules, protocols, algorithms, or the like which the UE may use to perform the mapping. Examples of the mapping are demonstrated in the CBSR mapping schemes 500-b and 500-c. The UE may use the CBSR mapping scheme to map respective codebook configurations to CBSR configurations. In other words, the UE may associate each codebook configuration to a CBSR configuration based on the CBSR mapping scheme received from the network entity. For example, the UE may map the codebook configuration 505-a and the codebook configuration 505-c to the CBSR configuration 510-a. Additionally, or alternatively, the UE may map the codebook configuration 505-b to the CBSR configuration 510-b.

In some examples, the mapping of multiple codebook configurations to a CBSR configuration may reduce overhead. For example, the association of multiple codebook configurations to a same CBSR configuration may reduce a quantity of CBSR configurations indicated by the network entity, thus reducing the overhead associated with the CBSR indication including the quantity of CBSR configurations.

In the example of FIG. 5B, the UE may receive an indication to perform a first type of translation between the CBSR configurations 510 and the codebook configurations 505. The first type of translation may correspond to a first mapping shown in the example of the CBSR mapping scheme 500-b. For example, the UE may map a codebook configuration 505-d and a codebook configuration 505-e to a CBSR table 515-a (e.g., CBSR indication) according to the indicated translation. The indicated translation may include a set of rules, protocols, algorithms, or the like based on which the UE may perform the mapping.

In the example of FIG. 5B, the translation may indicate a translation ratio and may instruct the UE to calculate an adjusted value for a respective index of each entry of a codebook based on the translation ratio. The UE may calculate an adjusted value for a respective index of each entry of a quantity of entries in each codebook configuration. For example, the UE may convert an index of the respective codebook to an index of the CBSR table 515-a using Equation 5. In Equation 5, A_cbsr may be a quantity of bits (e.g., a resolution) of the CBSR table 515-a, A_cb may be a quantity of bits (e.g., a resolution) of the respective codebook configuration, i_cb may be an index of the respective codebook, and i_cbsr may be an index of the CBSR table 515-a.

In some examples, the quantity of bits of the CBSR table 515-a may be given by Equation 6, where N_cbsr is a quantity of antenna elements of the CBSR, O_cbsr is an oversampling ratio of the CBSR, N_cb is a quantity of antenna elements of the codebook, and O_cb is an oversampling ratio of the codebook.
A_cbsr=N_cbsr×O_cbsrA_cb=N_cb×O_cb (6)

The UE may calculate which index of the CBSR table 515-a corresponds to each index of the codebook configuration 505-d and the codebook configuration 505-e according to Equation 5. For example, the codebook configuration 505-d may have a quantity of antenna elements N₁=8 and an oversampling ratio O₁=2 (and, thus, a quantity of bits A_cb=16) while a size of the CBSR table 515-a may be associated with a quantity of antenna elements N₁=4 and an oversampling ratio O₁=2 (and, thus, a quantity of bits A_cbsr=8) . Additionally, or alternatively, the codebook configuration 505-e may have a quantity of antenna elements N₁=6 and an oversampling ratio O₁=2 (and, thus, a quantity of bits A_cb=12) .

As an example of an index mapping, the UE may determine whether a first index 520-a (e.g., i_cb=1) of the codebook configuration maps to a restricted bit 305 of the CBSR table 515-a according to Equation 5, which yields a calculated i_cbsr of 0.5 (e.g., according to the inputs A_cb=16 and A_cbsr=8) . The calculated i_cbsr (e.g., rounded up) may be a first index 520-b of the CBSR table 515-a, which includes a restricted bit 305. The UE may perform a same calculation for the second index, the third index, and so on (e.g., until each index of the codebook configuration 515-d is mapped to an index of the CBSR table 515-a) .

As another example of the index mapping, the UE may determine whether a sixth index 520-c (e.g., i_cb=6) of the codebook configuration maps to a restricted bit 305 of the CBSR table 515-a according to Equation 5, which yields a calculated i_cbsr of 4 (e.g., according to the inputs A_cb=12 and A_cbsr=8) . The calculated i_cbsr may be a fourth index 520-d of the CBSR table 515-a, which does not include a restricted bit 305. The UE may perform a same calculation for the second index, the third index, and so on (e.g., until each index of the codebook configuration 515-e is mapped to an index of the CBSR table 515-a) .

In the example of FIG. 5C, the UE may receive the indication of the translation, which may instruct the UE to map the CBSR table 515-b to a respective codebook configuration based on overlap between one or more ranges of indexes in the codebook with ranges or indexes in the CBSR table 515-a that have a first value (e.g., are restricted bits 305 with a value of zero, or some other value that indicates restricted bits 305) .

The UE may determine an overlap between one or more bits (e.g., restricted bits 305) of the CBSR table 515-b and the respective codebook configurations 505. For example, the UE may identify the bits of the codebook configuration 505-f and the codebook configuration 505-g overlapping the restricted bits 305 of the CBSR table 515-b. In some examples, the CBSR table 515-b may have a first range of bits, the codebook configuration 505-f may have a second range of bits, and the codebook configuration 505-g may have a third range of bits. The UE may identify restricted bits 305 of the first range of bits overlapping any bits of the second range and third range.

For example, the first range of the CBSR table 515-b may be defined as and the respective codebook ranges (e.g., the second range and the third range) may be defined asThe UE may evaluate, for each index of the respective codebook configurations, whether Equation 7, Equation 8, or Equation 9 is true for the given index.

A first index 520-e of the codebook configuration 505-f may not have the restricted bit 305 as it does not overlap with the restricted bits 305 of the CBSR table 515-b. Additionally, or alternatively, a first index 520-f of the codebook configuration 505-g may have the restricted bit 305 as it does overlap (e.g., at least partially) with a first index of the CBSR table 515-b which has the restricted bit 305.

The network entity may thereby reduce overhead by transmitting an indication of multiple codebook configurations 505 having various sizes, one or more CBSR configurations 510 having various sizes, and a translation (e.g., an algorithm, rule, protocol, or the like) for translating between a CBSR configuration 510 and a codebook configuration 505 having different sizes.

FIG. 6 shows an example of a process flow 600 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. In some examples, the process flow 600 may implement or be implemented by aspects of the wireless communications system 100, the wireless communications system 200, the payload reduction schemes 300, 400-a, and 400-b, and the CBSR mapping schemes 500-a, 500-b, and 500-c, as described with reference to FIGs. 1–5. For example, the process flow 600 may include a UE 115 and a network entity 105 which may be examples of corresponding devices as described with reference to FIGs. 1 and 2.

Alternative examples of the following may be implemented, where some steps are performed in a different order than described or are not performed at all. In some cases, steps may include additional features not mentioned below, or further steps may be added. Although the UE 115 and the network entity 105 are shown performing the operations of the process flow 600, some aspects of some operations may also be performed by one or more other wireless devices.

At 605, the network entity 105 may transmit a control message to the UE 115. For example, the network entity 105 may transmit a first control message (e.g., an RRC message) to the UE 115 indicating one or more reference signal resources. The reference signal resources may be CSI-RS resources, or some other type of resources.

At 610, the network entity 105 may transmit a channel report configuration to the UE 115. For example, the network entity 105 may transmit a second control message (e.g., an RRC message) that indicates a channel report configuration (e.g., a CSI report configuration) associated with the reference signal resources. The channel report configuration may include an indication of a codebook (or multiple codebooks) and a CBSR indication (or multiple CBSR indications) associated with a channel report.

Additionally, or alternatively, the channel report configuration may include an indication of multiple codebooks and information that maps each codebook of the multiple codebooks to a respective CBSR. For example, the channel report configuration may include an indication of the CBSR mapping schemes as described with reference to FIGs. 5A–5C.

In some examples, the CBSR indication may include a first quantity of bits that is less than a second quantity of entries (e.g., a quantity of precoders and/or beams) in the at least one codebook based on a payload reduction scheme. The payload reduction scheme may involve an indication of two one-dimensional bitmaps, an indication of ranges or restricted bits, a reduced resolution of the indication, or any combination thereof, as described with reference to FIGs. 3, 4A, and 4B.

The CBSR indication may be reduced according to the payload reduction scheme described with reference to FIG. 3. For example, the CBSR indication may include a first bitmap associated with a first subset of entries of the second quantity of entries in the codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the codebook. The first bitmap may point to precoders associated with a first quantity of antenna elements along a first dimension (e.g., a horizontal dimension) of an antenna panel and the second bitmap may point to precoders associated with a second quantity of antenna elements along a second dimension (e.g., a vertical dimension) of the antenna panel.

Additionally, or alternatively, the CBSR indication may be reduced according to the payload reduction scheme described with reference to FIG. 4A. For example, the CBSR indication may include indexes that point to a range of bits in a bitmap. The range of bits may be associated with precoding matrices that are unavailable for selection by the UE 115. For example, the range of bits may have entries set to zero. In some examples, the first index may point to a first bit in the bitmap (e.g., a start bit) while the second index may point to a second bit in the bitmap (e.g., an end bit) . The range of bits may include the first bit, the second bits, and any bits between the first bit and the second bit in the bitmap. In some examples, the CBSR indication may include multiple ranges of bits (e.g., multiple pairs of start bits and end bits) .

In some other examples, the CBSR indication may be reduced according to the payload reduction scheme described with reference to FIG. 4B. For example, the CBSR indication may include the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, where a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension. That is, the quantity of bits in the first dimension, the second dimension, or both may be reduced according to a down sampling factor. For example, the set of precoders may be associated with a first quantity of antenna elements along the first dimension (e.g., a horizontal dimension) of an antenna panel and a second quantity of antenna elements along the second dimension (e.g., a vertical dimension) of the antenna panel.

At 615, in some examples, the network entity 105 may transmit an indication of a down sampling factor to the UE 115. For example, the network entity 105 may transmit a third control message that indicates the down sampling factor. Additionally, or alternatively, the down sampling factor may be defined or known by the UE 115. The UE 115 may, based on receiving the down sampling factor, convert a bitmap received via the channel report configuration at 610 from a reduced resolution to a higher resolution to determine which precoders are indicated as unavailable by the bitmap.

At 620, in some examples, the UE 115 may translate a CBSR indication to a corresponding codebook configuration. For example, the UE 115 may calculate an adjusted value for a respective index of each entry in the codebook and select entries in the CBSR indication that are closest to the adjusted value for the codebook indexes. For example, the UE 115 may calculate the adjusted value for a respective index of each entry of the second quantity of entries in the codebook based on a translation ratio. The translation ratio may be based on a ratio of the first size of the CBSR indication and the second size of the codebookas described with reference to Equation 5. The UE may translate the CBSR indication to the codebook based on the adjusted values, as described with reference to FIG. 5B.

Additionally, or alternatively, at 620, as part of translating the CBSR indication, the UE 115 may determine an overlap between one or more first ranges of indexes in the codebook with one or more second ranges of indexes in the CBSR indication that have a first value (e.g., a zero entry) . The UE 115 may determine the overlap according to the CBSR mapping scheme as described with reference to FIG. 5C.

At 625, the network entity 105 may transmit reference signals to the UE 115. The network entity 105 may transmit one or more reference signals (e.g., CSI-RSs) via the reference signal resources (e.g., CSI-RS resources) indicated in the first control message at 605. At 630, the UE 115 may perform channel estimation based on measurements of the one or more reference signals received at 625.

At 635, the UE 115 may select one or more preferred PMIs. For example, the UE 115 may select the PMIs to include in the channel report based on the channel estimation performed at 640, based on the CBSR indication received via the channel report configuration at 610, or both. Additionally, or alternatively, the UE 115 may select the PMIs based on translating the first size of the CBSR indication to a second size of the codebook at 620 (e.g., according to the CBSR mapping schemes described with reference to FIG. 5) . In some examples, the UE 115 may select the PMIs based on calculating a product of two one-dimensional bitmaps, as described with reference to FIG. 3, based on decoding ranges in a bitmap, as described with reference to FIG. 4A, based on adjusting a resolution of a CBSR indication according to the down sampling factor indicated at 615, as described with reference to FIG. 4B, or any combination thereof. The PMIs selected by the UE 115 may correspond to beams the UE 115 would prefer the network entity 105 to use for subsequent communications. The UE 115 may select the PMIs based on the various CBSR indications as described herein in addition to the channel estimation performed by the UE 115.

At 640, the UE 115 may transmit a channel report to the network entity 105. The UE 115 may transmit the channel report (e.g., the CSI report) based on the reference signal resources indicated via the first control message at 605. For example, the channel report may be based on the channel estimation performed at 640. The channel report may include the one or more parameters measured via the received reference signals at 635, based on which the channel estimation is performed at 640. The channel report may include the one or more PMIs based on the CBSR indication. For example, the channel report may include the PMIs selected at 640.

FIG. 7 shows a block diagram 700 of a device 705 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a transmitter 715, and a communications manager 720. The device 705, or one or more components of the device 705 (e.g., the receiver 710, the transmitter 715, and the communications manager 720) , may include at least one processor, which may be coupled with at least one memory, to, individually or collectively, support or enable the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 710 may provide a 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 CBSR indication payload reduction) . Information may be passed on to other components of the device 705. The receiver 710 may utilize a single antenna or a set of multiple antennas.

The transmitter 715 may provide a means for transmitting signals generated by other components of the device 705. For example, the transmitter 715 may transmit 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 CBSR indication payload reduction) . In some examples, the transmitter 715 may be co-located with a receiver 710 in a transceiver module. The transmitter 715 may utilize a single antenna or a set of multiple antennas.

The communications manager 720, the receiver 710, the transmitter 715, or various combinations thereof or various components thereof may be examples of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 720, the receiver 710, the transmitter 715, or various combinations or components thereof may be capable of performing one or more of the functions described herein.

In some examples, the communications manager 720, the receiver 710, the transmitter 715, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include at least one of 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, discrete hardware components, or any combination thereof configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure. In some examples, at least one processor and at least one memory coupled with the at least one processor may be configured to perform one or more of the functions described herein (e.g., by one or more processors, individually or collectively, executing instructions stored in the at least one memory) .

Additionally, or alternatively, the communications manager 720, the receiver 710, the transmitter 715, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by at least one processor. If implemented in code executed by at least one processor, the functions of the communications manager 720, the receiver 710, the transmitter 715, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure) .

In some examples, the communications manager 720 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 710, the transmitter 715, or both. For example, the communications manager 720 may receive information from the receiver 710, send information to the transmitter 715, or be integrated in combination with the receiver 710, the transmitter 715, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 720 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 720 is capable of, configured to, or operable to support a means for receiving a first control message that indicates one or more reference signal resources. The communications manager 720 is capable of, configured to, or operable to support a means for receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The communications manager 720 is capable of, configured to, or operable to support a means for transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

By including or configuring the communications manager 720 in accordance with examples as described herein, the device 705 (e.g., at least one processor controlling or otherwise coupled with the receiver 710, the transmitter 715, the communications manager 720, or a combination thereof) may support techniques for more efficient utilization of communication resources.

FIG. 8 shows a block diagram 800 of a device 805 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 805 may be an example of aspects of a device 705 or a UE 115 as described herein. The device 805 may include a receiver 810, a transmitter 815, and a communications manager 820. The device 805, or one or more components of the device 805 (e.g., the receiver 810, the transmitter 815, and the communications manager 820) , may include at least one processor, which may be coupled with at least one memory, to support the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 810 may provide a 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 CBSR indication payload reduction) . Information may be passed on to other components of the device 805. The receiver 810 may utilize a single antenna or a set of multiple antennas.

The transmitter 815 may provide a means for transmitting signals generated by other components of the device 805. For example, the transmitter 815 may transmit 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 CBSR indication payload reduction) . In some examples, the transmitter 815 may be co-located with a receiver 810 in a transceiver module. The transmitter 815 may utilize a single antenna or a set of multiple antennas.

The device 805, or various components thereof, may be an example of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 820 may include an RS resource receiver 825, a channel report configuration receiver 830, a channel report transmitter 835, or any combination thereof. The communications manager 820 may be an example of aspects of a communications manager 720 as described herein. In some examples, the communications manager 820, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 810, the transmitter 815, or both. For example, the communications manager 820 may receive information from the receiver 810, send information to the transmitter 815, or be integrated in combination with the receiver 810, the transmitter 815, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 820 may support wireless communications in accordance with examples as disclosed herein. The RS resource receiver 825 is capable of, configured to, or operable to support a means for receiving a first control message that indicates one or more reference signal resources. The channel report configuration receiver 830 is capable of, configured to, or operable to support a means for receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The channel report transmitter 835 is capable of, configured to, or operable to support a means for transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

FIG. 9 shows a block diagram 900 of a communications manager 920 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The communications manager 920 may be an example of aspects of a communications manager 720, a communications manager 820, or both, as described herein. The communications manager 920, or various components thereof, may be an example of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 920 may include an RS resource receiver 925, a channel report configuration receiver 930, a channel report transmitter 935, a decoupled bitmap component 940, a bit range component 945, a resolution reduction component 950, a mapping component 955, a translation component 960, an RS receiver 965, a channel estimation component 970, a translation ratio component 975, or any combination thereof. Each of these components, or components or subcomponents thereof (e.g., one or more processors, one or more memories) , may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The communications manager 920 may support wireless communications in accordance with examples as disclosed herein. The RS resource receiver 925 is capable of, configured to, or operable to support a means for receiving a first control message that indicates one or more reference signal resources. The channel report configuration receiver 930 is capable of, configured to, or operable to support a means for receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The channel report transmitter 935 is capable of, configured to, or operable to support a means for transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

In some examples, to support receiving the second control message, the decoupled bitmap component 940 is capable of, configured to, or operable to support a means for receiving, via the second control message, the CBSR indication including a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, where the one or more PMIs included in the channel report are based on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

In some examples, the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel.

In some examples, to support receiving the second control message, the bit range component 945 is capable of, configured to, or operable to support a means for receiving, via the second control message, the CBSR indication including indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for selection by the UE, where the one or more PMIs included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.

In some examples, to support receiving the indexes, the bit range component 945 is capable of, configured to, or operable to support a means for receiving a first index that points to a first bit in the bitmap. In some examples, to support receiving the indexes, the bit range component 945 is capable of, configured to, or operable to support a means for receiving a second index that points to a second bit in the bitmap, where the at least one range of bits includes the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

In some examples, to support receiving the second control message, the resolution reduction component 950 is capable of, configured to, or operable to support a means for receiving, via the second control message, the CBSR indication including the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, where a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based on a down sampling factor in accordance with the payload reduction scheme, and where the one or more PMIs included in the channel report are based on values of the first quantity of bits in the CBSR indication.

In some examples, the resolution reduction component 950 is capable of, configured to, or operable to support a means for receiving a third control message that indicates the down sampling factor.

In some examples, the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel and a second quantity of antenna elements along the second dimension of the antenna panel.

In some examples, the mapping component 955 is capable of, configured to, or operable to support a means for receiving, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook is mapped to the CBSR indication. In some examples, the translation component 960 is capable of, configured to, or operable to support a means for selecting the one or more PMIs to include in the channel report based on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

In some examples, the translation ratio component 975 is capable of, configured to, or operable to support a means for calculating, based on a translation ratio, an adjusted value for a respective index of each entry of the second quantity of entries in the at least one codebook, where the translation ratio is based on a ratio of the first size of the CBSR indication and the second size of the at least one codebook. In some examples, the translation component 960 is capable of, configured to, or operable to support a means for selecting, for each entry of the second quantity of entries, an index in the CBSR indication that is closest to the adjusted value for the respective index of the entry, where the translation of the first size of the CBSR indication to the second size of the at least one codebook is based on the selecting.

In some examples, the translation of the first size of the CBSR indication to the second size of the at least one codebook is based on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the CBSR indication that have a first value.

In some examples, the RS receiver 965 is capable of, configured to, or operable to support a means for receiving one or more reference signals via the one or more reference signal resources. In some examples, the channel estimation component 970 is capable of, configured to, or operable to support a means for performing a channel estimation based on measurements of the one or more reference signals. In some examples, the channel report transmitter 935 is capable of, configured to, or operable to support a means for selecting the one or more PMIs to include in the channel report based on the channel estimation and the CBSR indication.

In some examples, the second quantity of entries in the at least one codebook are based on a quantity of antenna elements used for communications with the UE.

In some examples, the first control message, the second control message, or both include radio resource control messages.

FIG. 10 shows a diagram of a system 1000 including a device 1005 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 1005 may be an example of or include the components of a device 705, a device 805, or a UE 115 as described herein. The device 1005 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. The device 1005 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager 1020, an input/output (I/O) controller 1010, a transceiver 1015, an antenna 1025, at least one memory 1030, code 1035, and at least one processor 1040. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1045) .

The I/O controller 1010 may manage input and output signals for the device 1005. The I/O controller 1010 may also manage peripherals not integrated into the device 1005. In some cases, the I/O controller 1010 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1010 may utilize an operating system such as or another known operating system. Additionally, or alternatively, the I/O controller 1010 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1010 may be implemented as part of one or more processors, such as the at least one processor 1040. In some cases, a user may interact with the device 1005 via the I/O controller 1010 or via hardware components controlled by the I/O controller 1010.

In some cases, the device 1005 may include a single antenna 1025. However, in some other cases, the device 1005 may have more than one antenna 1025, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1015 may communicate bi-directionally, via the one or more antennas 1025, wired, or wireless links as described herein. For example, the transceiver 1015 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1015 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1025 for transmission, and to demodulate packets received from the one or more antennas 1025. The transceiver 1015, or the transceiver 1015 and one or more antennas 1025, may be an example of a transmitter 715, a transmitter 815, a receiver 710, a receiver 810, or any combination thereof or component thereof, as described herein.

The at least one memory 1030 may include random access memory (RAM) and read-only memory (ROM) . The at least one memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed by the at least one processor 1040, cause the device 1005 to perform various functions described herein. The code 1035 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1035 may not be directly executable by the at least one processor 1040 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 1030 may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The at least one processor 1040 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 at least one processor 1040 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the at least one processor 1040. The at least one processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., the at least one memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks supporting CBSR indication payload reduction) . For example, the device 1005 or a component of the device 1005 may include at least one processor 1040 and at least one memory 1030 coupled with or to the at least one processor 1040, the at least one processor 1040 and at least one memory 1030 configured to perform various functions described herein. In some examples, the at least one processor 1040 may include multiple processors and the at least one memory 1030 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein. In some examples, the at least one processor 1040 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 1040) and memory circuitry (which may include the at least one memory 1030) ) , or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. As such, the at least one processor 1040 or a processing system including the at least one processor 1040 may be configured to, configurable to, or operable to cause the device 1005 to perform one or more of the functions described herein. Further, as described herein, being “configured to, ” being “configurable to, ” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code stored in the at least one memory 1030 or otherwise, to perform one or more of the functions described herein.

The communications manager 1020 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1020 is capable of, configured to, or operable to support a means for receiving a first control message that indicates one or more reference signal resources. The communications manager 1020 is capable of, configured to, or operable to support a means for receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The communications manager 1020 is capable of, configured to, or operable to support a means for transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

By including or configuring the communications manager 1020 in accordance with examples as described herein, the device 1005 may support techniques for improved user experience related to reduced processing and more efficient utilization of communication resources.

In some examples, the communications manager 1020 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver 1015, the one or more antennas 1025, or any combination thereof. Although the communications manager 1020 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 1020 may be supported by or performed by the at least one processor 1040, the at least one memory 1030, the code 1035, or any combination thereof. For example, the code 1035 may include instructions executable by the at least one processor 1040 to cause the device 1005 to perform various aspects of CBSR indication payload reduction as described herein, or the at least one processor 1040 and the at least one memory 1030 may be otherwise configured to, individually or collectively, perform or support such operations.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 1105 may be an example of aspects of a network entity 105 as described herein. The device 1105 may include a receiver 1110, a transmitter 1115, and a communications manager 1120. The device 1105, or one or more components of the device 1105 (e.g., the receiver 1110, the transmitter 1115, and the communications manager 1120) , may include at least one processor, which may be coupled with at least one memory, to, individually or collectively, support or enable the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1110 may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . Information may be passed on to other components of the device 1105. In some examples, the receiver 1110 may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver 1110 may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

The transmitter 1115 may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device 1105. For example, the transmitter 1115 may output information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . In some examples, the transmitter 1115 may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter 1115 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1115 and the receiver 1110 may be co-located in a transceiver, which may include or be coupled with a modem.

The communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations thereof or various components thereof may be examples of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be capable of performing one or more of the functions described herein.

In some examples, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include at least one of a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure. In some examples, at least one processor and at least one memory coupled with the at least one processor may be configured to perform one or more of the functions described herein (e.g., by one or more processors, individually or collectively, executing instructions stored in the at least one memory) .

Additionally, or alternatively, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by at least one processor. If implemented in code executed by at least one processor, the functions of the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure) .

In some examples, the communications manager 1120 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 1110, the transmitter 1115, or both. For example, the communications manager 1120 may receive information from the receiver 1110, send information to the transmitter 1115, or be integrated in combination with the receiver 1110, the transmitter 1115, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1120 is capable of, configured to, or operable to support a means for transmitting a first control message that indicates one or more reference signal resources. The communications manager 1120 is capable of, configured to, or operable to support a means for transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The communications manager 1120 is capable of, configured to, or operable to support a means for receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

By including or configuring the communications manager 1120 in accordance with examples as described herein, the device 1105 (e.g., at least one processor controlling or otherwise coupled with the receiver 1110, the transmitter 1115, the communications manager 1120, or a combination thereof) may support techniques for more efficient utilization of communication resources.

FIG. 12 shows a block diagram 1200 of a device 1205 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 1205 may be an example of aspects of a device 1105 or a network entity 105 as described herein. The device 1205 may include a receiver 1210, a transmitter 1215, and a communications manager 1220. The device 1205, or one or more components of the device 1205 (e.g., the receiver 1210, the transmitter 1215, and the communications manager 1220) , may include at least one processor, which may be coupled with at least one memory, to support the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1210 may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . Information may be passed on to other components of the device 1205. In some examples, the receiver 1210 may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver 1210 may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

The transmitter 1215 may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device 1205. For example, the transmitter 1215 may output information such as user data, control information, or any combination thereof (e.g., I/Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . In some examples, the transmitter 1215 may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter 1215 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1215 and the receiver 1210 may be co-located in a transceiver, which may include or be coupled with a modem.

The device 1205, or various components thereof, may be an example of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 1220 may include an RS resource transmitter 1225, a channel report configuration transmitter 1230, a channel report receiver 1235, or any combination thereof. The communications manager 1220 may be an example of aspects of a communications manager 1120 as described herein. In some examples, the communications manager 1220, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 1210, the transmitter 1215, or both. For example, the communications manager 1220 may receive information from the receiver 1210, send information to the transmitter 1215, or be integrated in combination with the receiver 1210, the transmitter 1215, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. The RS resource transmitter 1225 is capable of, configured to, or operable to support a means for transmitting a first control message that indicates one or more reference signal resources. The channel report configuration transmitter 1230 is capable of, configured to, or operable to support a means for transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The channel report receiver 1235 is capable of, configured to, or operable to support a means for receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

FIG. 13 shows a block diagram 1300 of a communications manager 1320 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The communications manager 1320 may be an example of aspects of a communications manager 1120, a communications manager 1220, or both, as described herein. The communications manager 1320, or various components thereof, may be an example of means for performing various aspects of CBSR indication payload reduction as described herein. For example, the communications manager 1320 may include an RS resource transmitter 1325, a channel report configuration transmitter 1330, a channel report receiver 1335, a decoupled bitmap component 1340, a bit range component 1345, a resolution reduction component 1350, a translation component 1355, an RS transmitter 1360, or any combination thereof. Each of these components, or components or subcomponents thereof (e.g., one or more processors, one or more memories) , may communicate, directly or indirectly, with one another (e.g., via one or more buses) which may include communications within a protocol layer of a protocol stack, communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with a network entity 105, between devices, components, or virtualized components associated with a network entity 105) , or any combination thereof.

The communications manager 1320 may support wireless communications in accordance with examples as disclosed herein. The RS resource transmitter 1325 is capable of, configured to, or operable to support a means for transmitting a first control message that indicates one or more reference signal resources. The channel report configuration transmitter 1330 is capable of, configured to, or operable to support a means for transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The channel report receiver 1335 is capable of, configured to, or operable to support a means for receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

In some examples, to support transmitting the second control message, the decoupled bitmap component 1340 is capable of, configured to, or operable to support a means for transmitting, via the second control message, the CBSR indication including a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, where the one or more PMIs included in the channel report are based on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

In some examples, the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel at the network entity and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel at the network entity.

In some examples, to support transmitting the second control message, the bit range component 1345 is capable of, configured to, or operable to support a means for transmitting, via the second control message, the CBSR indication including indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for inclusion in the channel report, where the one or more PMIs included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.

In some examples, to support transmitting the indexes, the bit range component 1345 is capable of, configured to, or operable to support a means for transmitting a first index that points to a first bit in the bitmap. In some examples, to support transmitting the indexes, the bit range component 1345 is capable of, configured to, or operable to support a means for transmitting a second index that points to a second bit in the bitmap, where the at least one range of bits includes the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

In some examples, to support transmitting the second control message, the resolution reduction component 1350 is capable of, configured to, or operable to support a means for transmitting, via the second control message, the CBSR indication including the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, where a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based on a down sampling factor in accordance with the payload reduction scheme, and where the one or more PMIs included in the channel report are based on values of the first quantity of bits in the CBSR indication.

In some examples, the resolution reduction component 1350 is capable of, configured to, or operable to support a means for transmitting a third control message that indicates the down sampling factor.

In some examples, the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel at the network entity and a second quantity of antenna elements along the second dimension of the antenna panel at the network entity.

In some examples, the translation component 1355 is capable of, configured to, or operable to support a means for transmitting, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook is mapped to the CBSR indication, and where the one or more PMIs in the channel report are based on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

In some examples, the translation of the first size of the CBSR indication to the second size of the at least one codebook is based on a ratio of the first size of the CBSR indication and the second size of the at least one codebook.

In some examples, the RS transmitter 1360 is capable of, configured to, or operable to support a means for transmitting one or more reference signals via the one or more reference signal resources, where the one or more PMIs in the channel report are based on the one or more reference signals.

In some examples, the second quantity of entries in the at least one codebook are based on a quantity of antenna elements used for communications by the network entity.

FIG. 14 shows a diagram of a system 1400 including a device 1405 that supports CBSR indication payload reduction in accordance with one or more aspects of the present disclosure. The device 1405 may be an example of or include the components of a device 1105, a device 1205, or a network entity 105 as described herein. The device 1405 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, which may include communications over one or more wired interfaces, over one or more wireless interfaces, or any combination thereof. The device 1405 may include components that support outputting and obtaining communications, such as a communications manager 1420, a transceiver 1410, an antenna 1415, at least one memory 1425, code 1430, and at least one processor 1435. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1440) .

The transceiver 1410 may support bi-directional communications via wired links, wireless links, or both as described herein. In some examples, the transceiver 1410 may include a wired transceiver and may communicate bi-directionally with another wired transceiver. Additionally, or alternatively, in some examples, the transceiver 1410 may include a wireless transceiver and may communicate bi-directionally with another wireless transceiver. In some examples, the device 1405 may include one or more antennas 1415, which may be capable of transmitting or receiving wireless transmissions (e.g., concurrently) . The transceiver 1410 may also include a modem to modulate signals, to provide the modulated signals for transmission (e.g., by one or more antennas 1415, by a wired transmitter) , to receive modulated signals (e.g., from one or more antennas 1415, from a wired receiver) , and to demodulate signals. In some implementations, the transceiver 1410 may include one or more interfaces, such as one or more interfaces coupled with the one or more antennas 1415 that are configured to support various receiving or obtaining operations, or one or more interfaces coupled with the one or more antennas 1415 that are configured to support various transmitting or outputting operations, or a combination thereof. In some implementations, the transceiver 1410 may include or be configured for coupling with one or more processors or one or more memory components that are operable to perform or support operations based on received or obtained information or signals, or to generate information or other signals for transmission or other outputting, or any combination thereof. In some implementations, the transceiver 1410, or the transceiver 1410 and the one or more antennas 1415, or the transceiver 1410 and the one or more antennas 1415 and one or more processors or one or more memory components (e.g., the at least one processor 1435, the at least one memory 1425, or both) , may be included in a chip or chip assembly that is installed in the device 1405. In some examples, the transceiver 1410 may be operable to support communications via one or more communications links (e.g., a communication link 125, a backhaul communication link 120, a midhaul communication link 162, a fronthaul communication link 168) .

The at least one memory 1425 may include RAM, ROM, or any combination thereof. The at least one memory 1425 may store computer-readable, computer-executable code 1430 including instructions that, when executed by one or more of the at least one processor 1435, cause the device 1405 to perform various functions described herein. The code 1430 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1430 may not be directly executable by a processor of the at least one processor 1435 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 1425 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. In some examples, the at least one processor 1435 may include multiple processors and the at least one memory 1425 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories which may, individually or collectively, be configured to perform various functions herein (for example, as part of a processing system) .

The at least one processor 1435 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA, a microcontroller, a programmable logic device, discrete gate or transistor logic, a discrete hardware component, or any combination thereof) . In some cases, the at least one processor 1435 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into one or more of the at least one processor 1435. The at least one processor 1435 may be configured to execute computer-readable instructions stored in a memory (e.g., one or more of the at least one memory 1425) to cause the device 1405 to perform various functions (e.g., functions or tasks supporting CBSR indication payload reduction) . For example, the device 1405 or a component of the device 1405 may include at least one processor 1435 and at least one memory 1425 coupled with one or more of the at least one processor 1435, the at least one processor 1435 and the at least one memory 1425 configured to perform various functions described herein. The at least one processor 1435 may be an example of a cloud-computing platform (e.g., one or more physical nodes and supporting software such as operating systems, virtual machines, or container instances) that may host the functions (e.g., by executing code 1430) to perform the functions of the device 1405. The at least one processor 1435 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in the device 1405 (such as within one or more of the at least one memory 1425) . In some examples, the at least one processor 1435 may include multiple processors and the at least one memory 1425 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein. In some examples, the at least one processor 1435 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 1435) and memory circuitry (which may include the at least one memory 1425) ) , or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. As such, the at least one processor 1435 or a processing system including the at least one processor 1435 may be configured to, configurable to, or operable to cause the device 1405 to perform one or more of the functions described herein. Further, as described herein, being “configured to, ” being “configurable to, ” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code stored in the at least one memory 1425 or otherwise, to perform one or more of the functions described herein.

In some examples, a bus 1440 may support communications of (e.g., within) a protocol layer of a protocol stack. In some examples, a bus 1440 may support communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack) , which may include communications performed within a component of the device 1405, or between different components of the device 1405 that may be co-located or located in different locations (e.g., where the device 1405 may refer to a system in which one or more of the communications manager 1420, the transceiver 1410, the at least one memory 1425, the code 1430, and the at least one processor 1435 may be located in one of the different components or divided between different components) .

In some examples, the communications manager 1420 may manage aspects of communications with a core network 130 (e.g., via one or more wired or wireless backhaul links) . For example, the communications manager 1420 may manage the transfer of data communications for client devices, such as one or more UEs 115. In some examples, the communications manager 1420 may manage communications with other network entities 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other network entities 105. In some examples, the communications manager 1420 may support an X2 interface within an LTE/LTE-A wireless communications network technology to provide communication between network entities 105.

The communications manager 1420 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1420 is capable of, configured to, or operable to support a means for transmitting a first control message that indicates one or more reference signal resources. The communications manager 1420 is capable of, configured to, or operable to support a means for transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The communications manager 1420 is capable of, configured to, or operable to support a means for receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication.

By including or configuring the communications manager 1420 in accordance with examples as described herein, the device 1405 may support techniques for improved user experience related to reduced processing and more efficient utilization of communication resources.

In some examples, the communications manager 1420 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the transceiver 1410, the one or more antennas 1415 (e.g., where applicable) , or any combination thereof. Although the communications manager 1420 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 1420 may be supported by or performed by the transceiver 1410, one or more of the at least one processor 1435, one or more of the at least one memory 1425, the code 1430, or any combination thereof (for example, by a processing system including at least a portion of the at least one processor 1435, the at least one memory 1425, the code 1430, or any combination thereof) . For example, the code 1430 may include instructions executable by one or more of the at least one processor 1435 to cause the device 1405 to perform various aspects of CBSR indication payload reduction as described herein, or the at least one processor 1435 and the at least one memory 1425 may be otherwise configured to, individually or collectively, perform or support such operations.

FIG. 15 shows a flowchart illustrating a method 1500 that supports CBSR indication payload reduction in accordance with aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE or its components as described herein. For example, the operations of the method 1500 may be performed by a UE 115 as described with reference to FIGs. 1 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1505, the method may include receiving a first control message that indicates one or more reference signal resources. The operations of block 1505 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1505 may be performed by an RS resource receiver 925 as described with reference to FIG. 9.

At 1510, the method may include receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The operations of block 1510 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1510 may be performed by a channel report configuration receiver 930 as described with reference to FIG. 9.

At 1515, the method may include transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication. The operations of block 1515 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1515 may be performed by a channel report transmitter 935 as described with reference to FIG. 9.

FIG. 16 shows a flowchart illustrating a method 1600 that supports CBSR indication payload reduction in accordance with aspects of the present disclosure. The operations of the method 1600 may be implemented by a UE or its components as described herein. For example, the operations of the method 1600 may be performed by a UE 115 as described with reference to FIGs. 1 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1605, the method may include receiving a first control message that indicates one or more reference signal resources. The operations of block 1605 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed by an RS resource receiver 925 as described with reference to FIG. 9.

At 1610, the method may include receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. In some examples, the method may include receiving, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook is mapped to the CBSR indication. The operations of block 1610 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1610 may be performed by a channel report configuration receiver 930, a mapping component 955, or both as described with reference to FIG. 9.

At 1615, the method may include selecting the one or more PMIs to include in the channel report based on a translation of a first size of the CBSR indication to a second size of the at least one codebook. The operations of block 1615 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed by a translation component 960 as described with reference to FIG. 9.

At 1620, the method may include transmitting, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication. The operations of block 1620 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1620 may be performed by a channel report transmitter 935 as described with reference to FIG. 9.

FIG. 17 shows a flowchart illustrating a method 1700 that supports CBSR indication payload reduction in accordance with aspects of the present disclosure. The operations of the method 1700 may be implemented by a network entity or its components as described herein. For example, the operations of the method 1700 may be performed by a network entity as described with reference to FIGs. 1 through 6 and 11 through 14. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware.

At 1705, the method may include transmitting a first control message that indicates one or more reference signal resources. The operations of block 1705 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1705 may be performed by an RS resource transmitter 1325 as described with reference to FIG. 13.

At 1710, the method may include transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. The operations of block 1710 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1710 may be performed by a channel report configuration transmitter 1330 as described with reference to FIG. 13.

At 1715, the method may include receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication. The operations of block 1715 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1715 may be performed by a channel report receiver 1335 as described with reference to FIG. 13.

FIG. 18 shows a flowchart illustrating a method 1800 that supports CBSR indication payload reduction in accordance with aspects of the present disclosure. The operations of the method 1800 may be implemented by a network entity or its components as described herein. For example, the operations of the method 1800 may be performed by a network entity as described with reference to FIGs. 1 through 6 and 11 through 14. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware.

At 1805, the method may include transmitting a first control message that indicates one or more reference signal resources. The operations of block 1805 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1805 may be performed by an RS resource transmitter 1325 as described with reference to FIG. 13. [0253]At 1810, the method may include transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration including an indication of at least one codebook and a CBSR indication associated with a channel report, where the CBSR indication includes a first quantity of bits that is less than a second quantity of entries in the at least one codebook based on a payload reduction scheme. In some examples, the method may include transmitting, via the channel report configuration, an indication of a set of multiple codebooks including the at least one codebook and information that maps each codebook of the set of multiple codebooks to a respective CBSR, where the at least one codebook is mapped to the CBSR indication, and where the one or more PMIs in the channel report are based on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

The operations of block 1810 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1810 may be performed by a channel report configuration transmitter 1330, a translation component 1355, or both as described with reference to FIG. 13.

At 1815, the method may include receiving, based on the one or more reference signal resources, the channel report, where the channel report includes one or more PMIs based on the CBSR indication. The operations of block 1815 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1815 may be performed by a channel report receiver 1335 as described with reference to FIG. 13.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communications at a UE, comprising: receiving a first control message that indicates one or more reference signal resources; receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a CBSR indication associated with a channel report, wherein the CBSR indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and transmitting, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more PMIs based at least in part on the CBSR indication.

Aspect 2: The method of aspect 1, wherein receiving the second control message comprises: receiving, via the second control message, the CBSR indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more PMIs included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

Aspect 3: The method of aspect 2, wherein the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel.

Aspect 4: The method of any of aspects 1 through 3, wherein receiving the second control message comprises: receiving, via the second control message, the CBSR indication comprising indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for selection by the UE, wherein the one or more PMIs included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.

Aspect 5: The method of aspect 4, wherein receiving the indexes comprises: receiving a first index that points to a first bit in the bitmap; and receiving a second index that points to a second bit in the bitmap, wherein the at least one range of bits comprises the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

Aspect 6: The method of any of aspects 1 through 5, wherein receiving the second control message comprises: receiving, via the second control message, the CBSR indication comprising the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, wherein a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based at least in part on a down sampling factor in accordance with the payload reduction scheme, and wherein the one or more PMIs included in the channel report are based at least in part on values of the first quantity of bits in the CBSR indication.

Aspect 7: The method of aspect 6, further comprising: receiving a third control message that indicates the down sampling factor.

Aspect 8: The method of any of aspects 6 through 7, wherein the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel and a second quantity of antenna elements along the second dimension of the antenna panel.

Aspect 9: The method of any of aspects 1 through 8, further comprising: receiving, via the channel report configuration, an indication of a plurality of codebooks including the at least one codebook and information that maps each codebook of the plurality of codebooks to a respective CBSR, wherein the at least one codebook is mapped to the CBSR indication; and selecting the one or more PMIs to include in the channel report based at least in part on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

Aspect 10: The method of aspect 9, further comprising: calculating, based at least in part on a translation ratio, an adjusted value for a respective index of each entry of the second quantity of entries in the at least one codebook, wherein the translation ratio is based at least in part on a ratio of the first size of the CBSR indication and the second size of the at least one codebook; and selecting, for each entry of the second quantity of entries, an index in the CBSR indication that is closest to the adjusted value for the respective index of the entry, wherein the translation of the first size of the CBSR indication to the second size of the at least one codebook is based at least in part on the selecting.

Aspect 11: The method of any of aspects 9 through 10, wherein the translation of the first size of the CBSR indication to the second size of the at least one codebook is based at least in part on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the CBSR indication that have a first value.

Aspect 12: The method of any of aspects 1 through 11, further comprising: receiving one or more reference signals via the one or more reference signal resources; performing a channel estimation based at least in part on measurements of the one or more reference signals; and selecting the one or more PMIs to include in the channel report based at least in part on the channel estimation and the CBSR indication.

Aspect 13: The method of any of aspects 1 through 12, wherein the second quantity of entries in the at least one codebook are based at least in part on a quantity of antenna elements used for communications with the UE.

Aspect 14: The method of any of aspects 1 through 13, wherein the first control message, the second control message, or both comprise RRC messages.

Aspect 15: A method for wireless communications at a network entity, comprising: transmitting a first control message that indicates one or more reference signal resources; transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a CBSR indication associated with a channel report, wherein the CBSR indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and receiving, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more PMIs based at least in part on the CBSR indication.

Aspect 16: The method of aspect 15, wherein transmitting the second control message comprises: transmitting, via the second control message, the CBSR indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more PMIs included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.

Aspect 17: The method of aspect 16, wherein the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel at the network entity and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel at the network entity.

Aspect 18: The method of any of aspects 15 through 17, wherein transmitting the second control message comprises: transmitting, via the second control message, the CBSR indication comprising indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for inclusion in the channel report, wherein the one or more PMIs included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.

Aspect 19: The method of aspect 18, wherein transmitting the indexes comprises: transmitting a first index that points to a first bit in the bitmap; and transmitting a second index that points to a second bit in the bitmap, wherein the at least one range of bits comprises the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.

Aspect 20: The method of any of aspects 15 through 19, wherein transmitting the second control message comprises: transmitting, via the second control message, the CBSR indication comprising the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, wherein a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based at least in part on a down sampling factor in accordance with the payload reduction scheme, and wherein the one or more PMIs included in the channel report are based at least in part on values of the first quantity of bits in the CBSR indication.

Aspect 21: The method of aspect 20, further comprising: transmitting a third control message that indicates the down sampling factor.

Aspect 22: The method of any of aspects 20 through 21, wherein the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel at the network entity and a second quantity of antenna elements along the second dimension of the antenna panel at the network entity.

Aspect 23: The method of any of aspects 15 through 22, further comprising: transmitting, via the channel report configuration, an indication of a plurality of codebooks including the at least one codebook and information that maps each codebook of the plurality of codebooks to a respective CBSR, wherein the at least one codebook is mapped to the CBSR indication, and wherein the one or more PMIs in the channel report are based at least in part on a translation of a first size of the CBSR indication to a second size of the at least one codebook.

Aspect 24: The method of aspect 23, wherein the translation of the first size of the CBSR indication to the second size of the at least one codebook is based at least in part on a ratio of the first size of the CBSR indication and the second size of the at least one codebook.

Aspect 25: The method of aspect 24, wherein the translation of the first size of the CBSR indication to the second size of the at least one codebook is based at least in part on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the CBSR indication that have a first value.

Aspect 26: The method of any of aspects 15 through 25, further comprising: transmitting one or more reference signals via the one or more reference signal resources, wherein the one or more PMIs in the channel report are based at least in part on the one or more reference signals.

Aspect 27: The method of any of aspects 15 through 26, wherein the second quantity of entries in the at least one codebook are based at least in part on a quantity of antenna elements used for communications by the network entity.

Aspect 28: The method of any of aspects 15 through 27, wherein the first control message, the second control message, or both comprise RRC messages.

Aspect 29: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 1 through 14.

Aspect 30: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 1 through 14.

Aspect 31: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 14.

Aspect 32: A network entity for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the network entity to perform a method of any of aspects 15 through 28.

Aspect 33: A network entity for wireless communications, comprising at least one means for performing a method of any of aspects 15 through 28.

Aspect 34: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of aspects 15 through 28.

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

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications 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, as well as other systems and radio technologies not explicitly mentioned herein.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor but, in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A 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) . Any functions or operations described herein as being capable of being performed by a processor may be performed by multiple processors that, individually or collectively, are capable of performing the described functions or operations.

The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. If implemented using software executed by a processor, the functions may be stored as or transmitted using one or more instructions or code of a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc. Disks may reproduce data magnetically, and discs may reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media. Any functions or operations described herein as being capable of being performed by a memory may be performed by multiple memories that, individually or collectively, are capable of performing the described functions or operations.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such 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) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

As used herein, including in the claims, the article “a” before a noun is open-ended and understood to refer to “at least one” of those nouns or “one or more” of those nouns. Thus, the terms “a, ” “at least one, ” “one or more, ” “at least one of one or more” may be interchangeable. For example, if a claim recites “acomponent” that performs one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components. Thus, the term “acomponent” having characteristics or performing functions may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent reference to a component introduced with the article “a” using the terms “the” or “said” may refer to any or all of the one or more components. For example, a component introduced with the article “a” may be understood to mean “one or more components, ” and referring to “the component” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ” Similarly, subsequent reference to a component introduced as “one or more components” using the terms “the” or “said” may refer to any or all of the one or more components. For example, referring to “the one or more components” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ”

The term “determine” or “determining” encompasses a variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information) , accessing (e.g., accessing data stored in memory) and the like. Also, “determining” can include resolving, obtaining, selecting, choosing, establishing, and other such similar actions.

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:

receive a first control message that indicates one or more reference signal resources;

receive a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a codebook subset restriction indication associated with a channel report, wherein the codebook subset restriction indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and

transmit, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more precoding matrix indicators based at least in part on the codebook subset restriction indication.
The UE of claim 1, wherein, to receive the second control message, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

receive, via the second control message, the codebook subset restriction indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more precoding matrix indicators included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.
The UE of claim 2, wherein the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel.
The UE of claim 1, wherein, to receive the second control message, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

receive, via the second control message, the codebook subset restriction indication comprising indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for selection by the UE, wherein the one or more precoding matrix indicators included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.
The UE of claim 4, wherein, to receive the indexes, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

receive a first index that points to a first bit in the bitmap; and

receive a second index that points to a second bit in the bitmap, wherein the at least one range of bits comprises the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.
The UE of claim 1, wherein, to receive the second control message, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

receive, via the second control message, the codebook subset restriction indication comprising the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, wherein a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based at least in part on a down sampling factor in accordance with the payload reduction scheme, and wherein the one or more precoding matrix indicators included in the channel report are based at least in part on values of the first quantity of bits in the codebook subset restriction indication.
The UE of claim 6, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive a third control message that indicates the down sampling factor.
The UE of claim 6, wherein the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel and a second quantity of antenna elements along the second dimension of the antenna panel.
The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive, via the channel report configuration, an indication of a plurality of codebooks including the at least one codebook and information that maps each codebook of the plurality of codebooks to a respective codebook subset restriction, wherein the at least one codebook is mapped to the codebook subset restriction indication; and

select the one or more precoding matrix indicators to include in the channel report based at least in part on a translation of a first size of the codebook subset restriction indication to a second size of the at least one codebook.
The UE of claim 9, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

calculate, based at least in part on a translation ratio, an adjusted value for a respective index of each entry of the second quantity of entries in the at least one codebook, wherein the translation ratio is based at least in part on a ratio of the first size of the codebook subset restriction indication and the second size of the at least one codebook; and

select, for each entry of the second quantity of entries, an index in the codebook subset restriction indication that is closest to the adjusted value for the respective index of the entry, wherein the translation of the first size of the codebook subset restriction indication to the second size of the at least one codebook is based at least in part on the selecting.
The UE of claim 9, wherein the translation of the first size of the codebook subset restriction indication to the second size of the at least one codebook is based at least in part on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the codebook subset restriction indication that have a first value.
The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive one or more reference signals via the one or more reference signal resources;

perform a channel estimation based at least in part on measurements of the one or more reference signals; and

select the one or more precoding matrix indicators to include in the channel report based at least in part on the channel estimation and the codebook subset restriction indication.
The UE of claim 1, wherein the second quantity of entries in the at least one codebook are based at least in part on a quantity of antenna elements used for communications with the UE.
A network entity, comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the network entity to:

transmit a first control message that indicates one or more reference signal resources;

transmit a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a codebook subset restriction indication associated with a channel report, wherein the codebook subset restriction indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and

receive, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more precoding matrix indicators based at least in part on the codebook subset restriction indication.
The network entity of claim 14, wherein, to transmit the second control message, the one or more processors are individually or collectively operable to execute the code to cause the network entity to:

transmit, via the second control message, the codebook subset restriction indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more precoding matrix indicators included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.
The network entity of claim 15, wherein the first bitmap points to precoders associated with a first quantity of antenna elements along a first dimension of an antenna panel at the network entity and the second bitmap points to precoders associated with a second quantity of antenna elements along a second dimension of the antenna panel at the network entity.
The network entity of claim 14, wherein, to transmit the second control message, the one or more processors are individually or collectively operable to execute the code to cause the network entity to:

transmit, via the second control message, the codebook subset restriction indication comprising indexes that point to at least one range of bits in a bitmap, the at least one range of bits associated with precoding matrices that are unavailable for inclusion in the channel report, wherein the one or more precoding matrix indicators included in the channel report are different than the precoding matrices indicated by the at least one range of bits in the bitmap.
The network entity of claim 17, wherein, to transmit the indexes, the one or more processors are individually or collectively operable to execute the code to cause the network entity to:

transmit a first index that points to a first bit in the bitmap; and

transmit a second index that points to a second bit in the bitmap, wherein the at least one range of bits comprises the first bit, the second bit, and any bits between the first bit and the second bit in the bitmap.
The network entity of claim 14, wherein, to transmit the second control message, the one or more processors are individually or collectively operable to execute the code to cause the network entity to:

transmit, via the second control message, the codebook subset restriction indication comprising the first quantity of bits that represents a corresponding set of precoders in a first dimension and a second dimension, wherein a respective quantity of precoders in each of the first dimension and the second dimension is less than a respective quantity of entries of the at least one codebook in each of the first dimension and the second dimension based at least in part on a down sampling factor in accordance with the payload reduction scheme, and wherein the one or more precoding matrix indicators included in the channel report are based at least in part on values of the first quantity of bits in the codebook subset restriction indication.
The network entity of claim 19, wherein the one or more processors are individually or collectively further operable to execute the code to cause the network entity to:

transmit a third control message that indicates the down sampling factor.
The network entity of claim 19, wherein the set of precoders is associated with a first quantity of antenna elements along the first dimension of an antenna panel at the network entity and a second quantity of antenna elements along the second dimension of the antenna panel at the network entity.
The network entity of claim 14, wherein the one or more processors are individually or collectively further operable to execute the code to cause the network entity to:

transmit, via the channel report configuration, an indication of a plurality of codebooks including the at least one codebook and information that maps each codebook of the plurality of codebooks to a respective codebook subset restriction, wherein the at least one codebook is mapped to the codebook subset restriction indication, and wherein the one or more precoding matrix indicators in the channel report are based at least in part on a translation of a first size of the codebook subset restriction indication to a second size of the at least one codebook.
The network entity of claim 22, wherein the translation of the first size of the codebook subset restriction indication to the second size of the at least one codebook is based at least in part on a ratio of the first size of the codebook subset restriction indication and the second size of the at least one codebook.
The network entity of claim 23, wherein the translation of the first size of the codebook subset restriction indication to the second size of the at least one codebook is based at least in part on an overlap between one or more first ranges of indexes in the at least one codebook with one or more second ranges of indexes in the codebook subset restriction indication that have a first value.
The network entity of claim 14, wherein the one or more processors are individually or collectively further operable to execute the code to cause the network entity to:

transmit one or more reference signals via the one or more reference signal resources, wherein the one or more precoding matrix indicators in the channel report are based at least in part on the one or more reference signals.
The network entity of claim 14, wherein:

the first control message, the second control message, or both comprise radio resource control messages.
A method for wireless communications at a user equipment (UE) , comprising:

receiving a first control message that indicates one or more reference signal resources;

receiving a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a codebook subset restriction indication associated with a channel report, wherein the codebook subset restriction indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and

transmitting, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more precoding matrix indicators based at least in part on the codebook subset restriction indication.
The method of claim 27, wherein receiving the second control message comprises:

receiving, via the second control message, the codebook subset restriction indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more precoding matrix indicators included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.
A method for wireless communications at a network entity, comprising:

transmitting a first control message that indicates one or more reference signal resources;

transmitting a second control message that indicates a channel report configuration associated with the one or more reference signal resources, the channel report configuration comprising an indication of at least one codebook and a codebook subset restriction indication associated with a channel report, wherein the codebook subset restriction indication comprises a first quantity of bits that is less than a second quantity of entries in the at least one codebook based at least in part on a payload reduction scheme; and

receiving, based at least in part on the one or more reference signal resources, the channel report, wherein the channel report comprises one or more precoding matrix indicators based at least in part on the codebook subset restriction indication.
The method of claim 29, wherein transmitting the second control message comprises:

transmitting, via the second control message, the codebook subset restriction indication comprising a first bitmap associated with a first subset of entries of the second quantity of entries in the at least one codebook and a second bitmap associated with a second subset of entries of the second quantity of entries in the at least one codebook, wherein the one or more precoding matrix indicators included in the channel report are based at least in part on a product of the first bitmap and the second bitmap in accordance with the payload reduction scheme.