WO2020181537A1

WO2020181537A1 - Bases selection in two-part uplink control information reporting

Info

Publication number: WO2020181537A1
Application number: PCT/CN2019/078037
Authority: WO
Inventors: Qiaoyu Li; Chenxi HAO; Liangming WU; Chao Wei
Original assignee: Qualcomm Incorporated
Priority date: 2019-03-13
Filing date: 2019-03-13
Publication date: 2020-09-17
Also published as: WO2020181613A1

Abstract

Methods, systems, and devices for wireless communication are described. Generally, the described techniques provide for efficiently reporting bases used to represent a preferred beam in channel state information (CSI) feedback to a base station. In particular, a user equipment (UE) may identify a preferred beam to be reported to a base station for each of one or more layers, and the UE may generate a two-stage CSI report that indicates the bases selected to represent the preferred beam on each layer. In the two-stage CSI report, a first stage of feedback may indicate a union set of the bases selected for all layers, and a second stage of feedback may indicate the subset of bases selected for each layer from the set of bases selected for all layers.

Description

BASES SELECTION IN TWO-PART UPLINK CONTROL INFORMATION REPORTING

BACKGROUND

The following relates generally to wireless communications, and more specifically to bases selection in two-part uplink control information (UCI) reporting.

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 frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) .

A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) . In some wireless communications systems, a UE may be configured to perform channel state information (CSI) measurements and report CSI feedback to a base station, such that the base station and the UE may be able to identify suitable configurations (e.g., beam configurations) for communicating with each other. In some cases, however, the content of a CSI report may be detailed, and it may be challenging for the UE to efficiently report the detailed content in the CSI report to a base station (e.g., with limited overhead and complexity) .

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support bases selection feedback in two-part uplink control information (UCI) reporting. Generally, the described techniques provide for efficiently reporting bases used to represent a preferred beam in channel state information (CSI) feedback to a base station. In particular, a user equipment (UE) may identify a preferred spatial beam to be reported to a base station for each of one or more layers, and the UE may generate a two-stage CSI report that indicates the transfer domain bases selected to represent the preferred spatial beam on each layer. In the two-stage CSI report, a first stage of feedback may indicate a union set of the bases selected for all layers, and a second stage of feedback may indicate the subset of bases selected for each layer from the set of bases selected for all layers. Using these techniques, the UE may be able to report the bases corresponding to a preferred beam for each layer with limited complexity (e.g., when the number of bases to be reported for each layer is different) .

A method of wireless communication at a UE is described. The method may include identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmitting the bases report via the two-part uplink control information reporting process.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two- part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmitting the bases report via the two-part uplink control information reporting process.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for generating the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE, and generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific bitmaps.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of layer-specific combinatorial numbers may be based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the first stage of the bases report during a first part of the two-part uplink control information reporting process, and transmitting the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage may be associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for generating the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE, and generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific bitmaps. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the combinatorial number of the first stage and the set of layer-specific combinatorial numbers of the second stage may be based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage may be associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for identifying that each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes a range of bases indices, generating the first stage of the bases report as one or more starting indices for each of the ranges of bases indices, and generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be the same for each of the ranges of bases indices. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the first stage of the bases report may include operations, features, means, or instructions for generating a starting index that may be common for each of the ranges of bases indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the first stage of the bases report may include operations, features, means, or instructions for generating a different starting index for at least some of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific bitmaps, where each of the set of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the second stage of the bases report may include operations, features, means, or instructions for generating a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the first stage of the bases report during a first part of the two-part uplink control information reporting process, and transmitting the second stage of the bases report during the first part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be different for at least some of the ranges of bases indices. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the first stage of the bases report may include operations, features, means, or instructions for generating a starting index that may be common for each of the ranges of bases indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the first stage of the bases report during a second part of the two-part uplink control information reporting process, and transmitting the second stage of the bases report during the second part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non- transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, at the UE, a sliding window length for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the sliding window lengths may include operations, features, means, or instructions for transmitting a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be received from the base station via one or more configuration messages.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report, and transmitting the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage may be associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE, and transmitting, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, with the bases report, an indication of the coefficients identifying the linear combination of the set of spatial beams, where the indication may be based on the generation of the bases report.

A method of wireless communication at a UE is described. The method may include identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmitting the bases report via the two-part uplink control information reporting process.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmitting the bases report via the two-part uplink control information reporting process.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for generating a set of layer-specific bitmaps. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report, and transmitting the set of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting the bases report may be associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for identifying that each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes a range of bases indices, identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be the same for each of the ranges of bases indices, and generating a starting index for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the sliding window length for each of the ranges of bases indices may include operations, features, means, or instructions for determining, at the UE, the sliding window length for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the sliding window length may include operations, features, means, or instructions for transmitting a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be received from the base station via one or more configuration messages. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for identifying that each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes a range of bases indices, identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be different for at least some of the ranges of bases indices, and generating a starting index for each of the ranges of bases indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each of the sliding window lengths may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, for each layer, the sliding window length may be the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the sliding window length for each of the ranges of bases indices may include operations, features, means, or instructions for determining, at the UE, a sliding window length for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

A method of wireless communication at a UE is described. The method may include identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmitting the bases report via the two-part uplink control information reporting process.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmit the bases report via the two-part uplink control information reporting process.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identifying that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmitting the bases report via the two-part uplink control information reporting process.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two- part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmit the bases report via the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for generating a single bitmap that includes all of the identified transfer domain bases for each of the layers.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report, and transmitting the bitmap during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting the bases report may be associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, generating the bases report may include operations, features, means, or instructions for identifying that the identified transfer domain bases may be represented within a sliding window that includes a range of bases indices, identifying a sliding window length for the ranges of bases indices, where the sliding window length may be the same for each layer, and generating a starting index for the sliding window, where the starting index may be the same for each layer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the sliding window length may include operations, features, means, or instructions for receiving the sliding window length via a configuration from the base station. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the bases report during a first part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the sliding window length for the ranges of bases indices may include operations, features, means, or instructions for determining, at the UE, a sliding window length for the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the bases report may include operations, features, means, or instructions for transmitting the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the sliding window length may include operations, features, means, or instructions for transmitting a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be received from the base station via one or more configuration messages.

A method of wireless communication at a base station is described. The method may include transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE, and receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific bitmaps. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of layer-specific combinatorial numbers may be based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report during a first part of the two-part uplink control information reporting process, and receiving the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report, and receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two- part uplink control information reporting process, where a number of bits used for both the first stage and the second stage may be associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases may be to be determined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be to be determined may be predetermined.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE, and receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific bitmaps. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the combinatorial number of the first stage and the set of layer-specific combinatorial numbers of the second stage may be based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report, and receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for both the first stage and the second stage may be associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report as one or more starting indices for corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes the respective range of bases indices, and receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be the same for each of the ranges of bases indices. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first stage of the bases report may include operations, features, means, or instructions for receiving a starting index that may be common for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first stage of the bases report may include operations, features, means, or instructions for receiving a different starting index for at least some of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific bitmaps, where each of the set of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report during a first part of the two-part uplink control information reporting process, and receiving the second stage of the bases report during the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a sliding window length for each of the ranges of bases indices, where the sliding window length may be different for at least some of the ranges of bases indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first stage of the bases report may include operations, features, means, or instructions for receiving a starting index that may be common for each of the ranges of bases indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first stage of the bases report may include operations, features, means, or instructions for receiving a different starting index for at least some of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific bitmaps, where each of the set of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second stage of the bases report may include operations, features, means, or instructions for receiving a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the first stage of the bases report during a second part of the two-part uplink control information reporting process, and receiving the second stage of the bases report during the second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process, and receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the sliding window lengths may include operations, features, means, or instructions for receiving a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be configured by the base station via one or more configuration messages.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report, and receiving the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for both the first stage and the second stage may be associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE, and receiving, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, with the bases report, an indication of the coefficients identifying the linear combination of the set of spatial beams, where the indication may be based on the generation of the bases report.

A method of wireless communication at a base station is described. The method may include transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a set of layer-specific bitmaps. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report, and receiving the set of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, where a number of bits used for the bases report may be associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a starting index for each of corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes the respective range of bases indices, where a sliding window length may be the same for each of the ranges of bases indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be predetermined. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the sliding window length may include operations, features, means, or instructions for receiving a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be transmitted by the base station via one or more configuration messages.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a starting index for each of corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases may be represented within a sliding window that includes the respective range of bases indices, where a sliding window length may be different for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each of the sliding window lengths may be predetermined.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, for each layer, the sliding window length may be the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices for at least one of the layers may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the sliding window length for each of the ranges of bases indices may include operations, features, means, or instructions for determining, at the UE, a sliding window length for each of the ranges of bases indices. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process, and transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the sliding window lengths may include operations, features, means, or instructions for receiving a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be received from the base station via one or more configuration messages.

A method of wireless communication at a base station is described. The method may include transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting one or more transmissions to a UE via a set of spatial transmit beams and receiving, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a transfer domain of the transfer domain bases may be based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a single bitmap that includes all of the identified transfer domain bases for each of the layers. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report, and receiving the bitmap during a second part of the two-part uplink control information reporting process, where a number of bits used for the bases report may be associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a starting index for a range of bases indices, where the identified transfer domain bases may be represented within a sliding window that includes the range of bases indices, where a sliding window length may be the same for each layer. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length may be predetermined.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the sliding window length via a configuration from the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving the bases report during a first part of the two-part uplink control information reporting process. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a quantity of transfer domain bases from which the identified transfer domain bases may be determined may be based on a configuration received from the base station or may be predetermined.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices may be a circular-shifted sliding window whose circulation may be associated with the range of bases indices, where a starting index of the circular-shifted sliding window may be greater than an ending index of the circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the range of bases indices may be a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window may be less than an ending index of the non-circular-shifted sliding window. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the bases report may include operations, features, means, or instructions for receiving a sliding window length for the ranges of bases indices, as determined at the UE, during a first part of the two-part uplink control information reporting process, and receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the sliding window length may include operations, features, means, or instructions for receiving a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sliding window combinations may be either predefined or may be received from the base station via one or more configuration messages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system that supports bases selection in two-part uplink control information (UCI) reporting in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of type-one channel state information (CSI) feedback in a wireless communications system.

FIG. 3 illustrates an example of type-two CSI feedback in a wireless communications system.

FIG. 4 illustrates an example of calculations used to reduce the overhead of type-two CSI feedback.

FIG. 5 illustrates an example of high-rank overhead compression in accordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a wireless communications system that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIG. 7 illustrates an example of sliding windows used to indicate selected bases in accordance with aspects of the present disclosure.

FIGs. 8 and 9 show block diagrams of devices that support bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIG. 10 shows a block diagram of a communications manager that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIG. 11 shows a diagram of a system including a device that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIGs. 12 and 13 show block diagrams of devices that support bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIG. 14 shows a block diagram of a communications manager that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIG. 15 shows a diagram of a system including a device that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

FIGs. 16 through 21 show flowcharts illustrating methods that support bases selection in two-part UCI reporting in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, a user equipment (UE) may be configured to perform channel state information (CSI) measurements and report CSI feedback to a base station, such that the base station and the UE may be able to identify suitable configurations (e.g., beam configurations) for communicating with each other. In such systems, once a UE identifies a preferred beam for communicating with a base station on a spatial layer, the UE may report the preferred beam in CSI feedback to the base station. In some examples, the UE may be configured to report the preferred beam in type-one CSI feedback. In such examples, the UE may report a specific index that corresponds to the preferred beam to the base station. In other examples, however, the UE may be configured to report the preferred beam in type-two CSI feedback. In such examples, the UE may have to report coefficients and bases that correspond to the preferred beam, and it may be challenging for the UE to report the bases that correspond to a preferred beam for one or more spatial layers with limited overhead and complexity.

As described herein, a UE may support efficient techniques for reporting bases used to represent a preferred beam in CSI feedback to a base station. In particular, a UE may identify a preferred spatial beam to be reported to a base station for each of one or more layers for each sub-band identified in the CSI reporting sub-bands, and the UE may generate a two-stage CSI report that indicates the transfer domain bases selected to represent the preferred spatial beam on each layer. In the two-stage CSI report, a first stage of feedback may indicate a union set of the bases selected for all layers, and a second stage of feedback may indicate the subset of bases selected for each layer from the set of bases selected for all layers. Using these techniques, the UE may be able to report the bases corresponding to a preferred beam for each layer with limited complexity (e.g., when the number of bases to be reported for each layer is different) .

Aspects of the disclosure introduced above are described below in the context of a wireless communications system. Examples of processes and signaling exchanges that support bases selection feedback in two-part uplink control information (UCI) reporting are then described. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to bases selection feedback in two-part UCI reporting.

FIG. 1 illustrates an example of a wireless communications system 100 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The wireless communications system 100 includes base stations 105, 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, or a New Radio (NR) network. In some cases, wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or some other suitable terminology. Wireless communications system 100 may include base stations 105 of different types (e.g., macro or small cell base stations) . The UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may utilize one or more carriers. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105 or downlink transmissions from a base station 105 to a UE 115. Downlink transmissions may also be called forward link transmissions while uplink transmissions may also be called reverse link transmissions.

The geographic coverage area 110 for a base station 105 may be divided into sectors making up a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term “cell” may refer to a logical communication entity used for communication with a base station 105 (e.g., over 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) ) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC) , narrowband Internet-of- Things (NB-IoT) , enhanced mobile broadband (eMBB) , or others) that may provide access for different types of devices. In some cases, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125. For example, a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defined frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN) ) and may be positioned according to a channel raster for discovery by UEs 115. Carriers may be downlink or uplink (e.g., in an FDD mode) , or be configured to carry downlink and uplink communications (e.g., in a TDD mode) . In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) .

UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also 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. A UE 115 may also be 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 also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.

Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1, N2, N3, or other interface) . Base stations 105 may communicate with one another over backhaul links 134 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) .

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) , which may include at least one mobility management entity (MME) , at least one serving gateway (S-GW) , and at least one Packet Data Network (PDN) gateway (P-GW) . The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to the network operators IP services. The operators IP services may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC) . Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP) . In some configurations, various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station 105) .

Wireless communications system 100 may operate using one or more frequency bands, typically 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, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. Wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that may be capable of tolerating interference from other users.

Wireless communications system 100 may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, wireless communications system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

In some cases, wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations 105 and UEs 115 may employ listen-before-talk (LBT) procedures to ensure a frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) , or a combination of both.

In some examples, base station 105 or 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. For example, wireless communications system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115) , where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which 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 bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where 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 base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or 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 signals propagating at 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 certain amplitude and phase offsets to signals carried via each of 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) .

In one example, a base station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try 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 applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal) . The single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions) .

In some cases, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, 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 cases, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-based network that operate according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data. At the Physical layer, transport channels may be mapped to physical channels.

Time intervals in LTE or NR may be expressed in multiples of a basic time unit, which may, for example, refer to a sampling period of T _s = 1/30,720,000 seconds. Time intervals of a communications resource may be organized according to radio frames each having a duration of 10 milliseconds (ms) , where the frame period may be expressed as T _f = 307,200 T _s. The radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the smallest scheduling unit of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In other cases, a smallest scheduling unit of the wireless communications system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs) .

In wireless communications system 100, a UE 115 may be configured to perform CSI measurements and report CSI feedback to a base station 105, such that the base station 105 and the UE 115 may be able to identify suitable configurations (e.g., beam configurations) for communicating with each other. In such systems, once a UE 115 identifies a preferred beam for communicating with a base station 105 on a spatial layer, the UE 115 may report the preferred beam in CSI feedback to the base station 105. The CSI feedback may be transmitted to the base station 105 in uplink control information (UCI) , where UCI may be separated into a first and second part. The first part of the UCI may have a fixed size (e.g., based on network configurations) and the second part of the UCI may have a variable size (e.g., where the variable size of the second part may be indicated to a base station 105 or otherwise derived by the base station 105 after successfully decoding the first part) . The payload size of the second part of UCI can be explicitly or implicitly derived after successfully decoding the first part of UCI. In some examples, the UE 115 may be configured to report the preferred beam in type-one CSI feedback. In such examples, the UE 115 may report a specific index that corresponds to the preferred beam to the base station 105. In other examples, however, the UE 115 may be configured to report the preferred beam in type-two CSI feedback. In such examples, the UE 115 may have to report coefficients and bases that correspond to the preferred beam.

FIG. 2 illustrates an example of type-one CSI feedback in a wireless communications system 200. In the example of FIG. 2, base station 105-a may transmit CSI-RS to the UE, and UE 115-a may firstly measure the channel using the received CSI-RS, then identify a preferred beam from the candidate beams for communicating with base station 105-aon a particular spatial layer (l) . Accordingly, UE 115-a may transmit an indication of the index (b _i) of the preferred beam to base station 105-a in a type-one CSI feedback report. For instance, the UE 115-a may transmit an indication of a precoding vector 205 for the lth layer in a precoding matrix indicator (PMI) in the CSI feedback report, where the precoding vector 205 indicates the index of the preferred beam. Since, in type-one CSI feedback, the UE 115-a may indicate the preferred beam by simply providing the index of the preferred beam to base station 105-a, this type of feedback may be associated with a smaller payload (e.g., compared to type-two CSI feedback) . However, the resolution of the beam indication may be lower.

FIG. 3 illustrates an example of type-two CSI feedback in a wireless communications system 300. In the example of FIG. 3, base station 105-b may also transmit CSI-RS to the UE, and UE 115-b may also firstly measure the channel using the received CSI-RS, then identify a preferred beam from the candidate beams for communicating with base station 105-b on a particular spatial layer (l) . Accordingly, UE 115-b may transmit an indication of quantized coefficients (c ₁, c ₂) and bases (b ₁, b ₂) that correspond to the preferred beam (e.g., c ₁b ₁+c ₂b ₂) in a type-two CSI feedback report. For instance, the UE 115-b may transmit an indication of a precoding vector 305 for the lth layer in a PMI in the CSI feedback report, where the precoding vector 305 indicates the coefficients and bases that correspond to the preferred beam. Since, in type-two CSI feedback, the UE 115-b may indicate the preferred beam by providing coefficients and bases that correspond to the preferred beam to base station 105-b, this type of feedback may be associated with a larger payload (e.g., compared to type-one CSI feedback) . However, the resolution of the beam indication may be higher.

As described above, a UE 115 may be able to use type-two CSI feedback to provide granular feedback to a base station 105 and indicate a preferred beam for communicating with the base station 105 with higher resolution. However, since the UE 115-b may have to report the coefficients and bases for a preferred beam for multiple layers and multiple sub-bands (e.g., where the number of sub-bands may be large) , the overhead of type-two CSI feedback may be high. As such, some wireless communications systems may support techniques for reducing the overhead of type-two CSI feedback.

FIG. 4 illustrates an example of calculations 400 used to reduce the overhead of type-two CSI feedback (e.g., in a single layer transmission) . In the example of FIG. 4, rather than reporting a matrix W that includes all values of bases and coefficients for all sub-bands (as illustrated in a first set of calculations 405) , a UE 115 may transfer the sub-band coefficients to another domain (e.g., discrete Fourier transform (DFT) basis domain) and select the bases (e.g., M bases) that have dominant coefficients associated with each beam in the transformed domain to include in the type-two CSI feedback (i.e., for each row in matrix V, only feedback non-zero entries or entries with values above a threshold (i.e., strong entries) ) . Thus, the overall number of coefficients and the overhead of the two-part CSI feedback may be reduced (e.g., though such compression may result in the beam construction at the network not being as accurate compared to beam construction performed using non-compressed coefficients) .

FIG. 5 illustrates an example of a high-rank overhead compression 500 in accordance with aspects of the present disclosure. In the example of FIG. 5, a UE 115 may be configured to transmit type-two CSI feedback for multiple layers 505-a and multiple sub-bands. Accordingly, for layer 1, the UE 115 may transmit an indication of a matrix W in the type-two CSI feedback, where the matrix W is determined using a spatial domain compression matrix representing the spatial beams to be linear combined to form the preferred spatial beam, a coefficient matrix (e.g., where each row corresponds one beam, and each element of a row may correspond to one transfer domain basis for frequency domain compression associated with this beam) , and a transfer domain compression bases matrix (e.g., where each row represents a transfer domain basis) . The UE 115 may use similar techniques to determine the matrix W to transmit in the type-two CSI feedback for layer 2 and layer 3 respectively. In some cases, the UE 115 may be configured to choose layer-specific coefficients for different layers based on layer-common or layer-specific choices of bases selection. Further, the UE 115 may be configured to choose same or different bases sets (or subsets) for different layers out of a predefined bases set. Thus, using the techniques described above, a UE 115 may identify a limited set of bases and coefficients to include in type-two CSI feedback for multiple layers and multiple sub-bands to reduce overhead.

Once the UE 115 identifies the bases used to represent a preferred beam for communicating with a base station 105 (e.g., with or without the techniques described above) , it may be appropriate for the UE 115 to report the bases in CSI feedback transmitted to base station 105. However, since the UE 115 may still have to report bases for multiple layers and multiple sub-bands, the overhead of type-two CSI feedback may still be high (e.g., even if a limited set of bases and coefficients is identified for reporting as described with reference to FIGs. 4 and 5) . Further, since the number of bases to report in CSI feedback may be the same or different for each layer (e.g., different layers may be configured with same or different values of M) , and a base station 105 may configure same or different sets of bases for bases selection for different layers (e.g., different layers may use layer-common or layer-different bases choices) , the complexity of type-two CSI feedback may also be high. As described herein, a UE 115 in wireless communications system 100 may support efficient techniques for reporting bases used to represent preferred beams for different layers in CSI feedback to a base station (e.g., with limited overhead and/or complexity) .

FIG. 6 illustrates an example of a wireless communications system 600 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. Wireless communications system 600 includes base station 105-c, which may be an example of a base station 105 described with reference to FIGs. 1-5. Wireless communications system 600 also includes UE 115-c, which may be an example of a UE 115 described with reference to FIGs. 1-5. Base station 105-c may provide communication coverage for a respective coverage area 110-a, which may be an example of a coverage area 110 described with reference to FIG. 1. Wireless communications system 600 may implement aspects of wireless communications system 100. For example, UE 115-c in wireless communications system 600 may support efficient techniques for reporting bases used to represent preferred beams for communicating with base station 105-c on one or more layers (e.g., with limited overhead and/or complexity) .

In particular, UE 115-c may identify a preferred spatial beam to be reported to base station 105-c for each of one or more layers, and UE 115-c may generate a two-stage CSI report that indicates the transfer domain bases selected to represent the preferred beam on each layer. In the two-stage CSI report, a first stage of feedback may indicate a union set of the transfer domain bases selected for all layers, and a second stage of feedback may indicate the subset of transfer domain bases selected for each layer from the set of bases selected for all layers. Using these techniques, the UE 115-c may be able to report the transfer domain bases corresponding to a preferred spatial beam for each layer with limited complexity (e.g., when the number of bases to be reported for each layer is different (or layer-specific) ) . Further, the overhead of the CSI feedback may be reduced since the UE 115-c may not have to indicate the transfer domain bases selected for each layer from the full set of all bases (i.e., instead, in the second stage of feedback, the UE 115-c may indicate the bases selected for each layer from the union set) .

In one example, UE 115-c may indicate the bases selected for each layer using bitmaps. For instance, UE 115-c may transmit a bitmap to indicate a union set of bases selected for all layers 610, and UE 115-c may transmit a bitmap to indicate the selected bases for each layer 610. Base station 105-c may indicate a quantity (N ₃) of transfer domain bases 615 from which UE 115-c is to select the bases to report in CSI feedback to base station 105-c. UE 115-c may then identify the bases 610-a to report for a first layer and the bases 610-b to report for a second layer from the set of bases 615. Once UE 115-c identifies the bases 610-aand 610-b, UE 115-c may transmit a bitmap (e.g., {0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0} ) of length N ₃ indicating a union set 620 that includes the set 625 of bases 610-a and bases 610-b to report for the first and second layers, and the UE 115-c may transmit a bitmap with a length equal to the length of the union set to indicate the bases 610 for each layer (e.g., a first bitmap {0, 1, 1, 0, 0} for layer 1 and a second bitmap {0, 0, 0, 1, 1} for layer 2) .

The above techniques for indicating the bases selected for each layer using bitmaps in two-stage feedback may be used if the bases selected for different layers are different (e.g., layer-different bases selection) . If, however, the bases selected for different layers are the same (e.g., layer-common bases selection) , UE 115-c may transmit one stage of CSI feedback including a single bitmap of length N ₃ indicating the set of selected bases for all layers. Further, in some cases, even if the bases selected for different layers are different (e.g., layer-specific bases selection) , UE 115-c may transmit one stage of CSI feedback including a bitmap of length N ₃ for each layer indicating the set of selected bases for each layer (i.e., the UE 115-c may not transmit an indication of a union set) .

In any of the examples described above for indicating bases using bitmaps, the two-stage or one-stage CSI feedback may be transmitted in a first part of UCI without further indications from the UE 115-c. However, if UE 115-c transmits the two-stage or one-stage CSI feedback in a second part of UCI (or a part of the two-stage CSI feedback in the second part of UCI) , UE 115-c may provide further indications in the first part of the UCI to base station 105-c to allow base station 105-c to determine the size of the second part of the UCI. In particular, for two-stage CSI feedback, if UE 115-c determines to transmit the bitmap indicating the union set in the second part of the UCI, UE 115-c may transmit an indication in the first part of the UCI of the number of ones in the union set bitmap such that base station 105-c may be able to determine the length of the bitmaps used to indicate the bases for each layer (i.e., since the length of these bitmaps corresponds to the number of ones in the union set bitmap) .

Further, for two-stage and one-stage CSI feedback, if UE 115-c transmits the bitmap or bitmaps indicating the bases selected in the second part of UCI, and the number of bases selected for each layer is not configured by base station 105-c, UE 115-c may transmit an indication in the first part of the UCI of the number of bases selected for each layer (e.g., the number of ones in the bitmaps used to indicate the bases selected for each layer) . Accordingly, the base station 105-c may be able to determine the length of other bitmaps, for example, used for other indications in the second part of the UCI (e.g., used to indicate coefficients) . If base station 105-c configures the number of bases for UE 115-c to select for each layer, UE 115-c may not have to transmit the indication in the first part of the UCI of the number of bases selected for each layer (i.e., since the base station 105-c may already have this information) .

In another example, UE 115-c may indicate the bases selected for each layer using combinatorial numbers (e.g., where a combinatorial number may correspond to a certain combination of bases and the combination of bases may be identified by referencing a look-up table using the combinatorial number) . For instance, UE 115-c may transmit a combinatorial number to indicate a union set of bases selected for all layers 610, and UE 115-c may transmit a combinatorial number to indicate the selected bases for each layer 610. Base station 105-c may indicate a quantity (N ₃) of transfer domain bases 615 from which UE 115-c is to select the bases to report in CSI feedback to base station 105-c. UE 115-c may then identify the bases 610-a to report for a first layer and the bases 610-b to report for a second layer from the set of bases 615. Once UE 115-c identifies the bases 610-a and 610-b, UE 115-c may transmit a combinatorial number (e.g., corresponding to bases b ₆-b ₁₁) indicating a union set 620 that includes the set 625 of bases 610-a and bases 610-b to report for the first and second layers, and the UE 115-c may transmit a combinatorial number to indicate the bases 610 for each layer (e.g., where UE 115-c may feedback a different number of bases for different layers (i.e., layer-different bases selection) ) .

In this example, UE 115-c may use

bits to indicate the combinatorial number that corresponds to the union set of bases selected for all layers, where M _com corresponds to the number of bases in the union set of bases selected for all layers. Further, in some cases, UE 115-c may use

bits to indicate the bases 610 for each layer, where M _r corresponds to the number of bases the UE 115-c is to feedback for a particular layer (e.g., the layer-specific bases selections) . In such cases, base station 105-c may indicate the value M _r for each layer (e.g., for rank indication = R, the rth layer feedbacks M _r bases, 1≤r≤R) . In other cases, UE 115-c may use a bitmap with a length of M _com to indicate the bases 610 for each layer (e.g., the layer-specific bases selections) .

In any of the examples described above for indicating bases using combinatorial numbers, the two-stage CSI feedback may be transmitted in a first part of UCI without further indications from the UE 115-c. However, if UE 115-c determines the transmit the two-stage CSI feedback in a second part of UCI (or a part of the two-stage CSI feedback in the second part of UCI) , UE 115-c may provide further indications in the first part of the UCI to base station 105-c to allow base station 105-c to determine the size of the second part of the UCI. In particular, if UE 115-c determines to transmit the combinatorial number that corresponds to the union set of bases selected for all layers in the second part of UCI, UE 115-c may transmit an indication in the first part of the UCI of the number of bases in the union set of bases selected for all layers (i.e., M _com) , since the number of bits used to indicate the combinatorial number that corresponds to the union set of bases selected for all layers (i.e.,

) is based on the value M _com.

In yet another example, UE 115-c may indicate the bases selected for each layer using a sliding window in combination with bitmaps and/or combinatorial numbers as described above (if necessary) . In some aspects of this example, UE 115-c may be configured to choose the same bases for different layers. In such aspects, if the M chosen bases to be reported have continuous indices (not shown) , UE 115-c may transmit an indication of a starting index of a sliding window of length M indicating the M chosen bases in the set of bases 615 using

bits. Alternatively, if the M chosen bases to be reported do not have continuous indices, UE 115-c may transmit an indication of a starting index of a sliding window (or union set 620) of length ΔM (e.g., starting at b ₆) that includes the M chosen bases using

bits. UE 115-c may then transmit a bitmap of length ΔM to indicate the M chosen bases 610 for each layer, or UE 115-c may transmit a combinatorial number using

bits to indicate the M chosen bases 610 for each layer.

In other aspects of this example, UE 115-c may be configured to choose the same number of bases for different layers (e.g., layer common M) , but UE 115-c may be configured to choose different bases for different layers. In such aspects, if the M chosen bases to be reported have continuous indices (not shown) and are the same for the different layers, UE 115-c may transmit an indication of a starting index of a sliding window of length M indicating the M chosen bases in the set of bases 615 using

bits. Alternatively, if the M chosen bases to be reported do not have continuous indices and/or are different for different layers, UE 115-c may transmit an indication of a starting index of a sliding window (or union set 620) of length ΔM (e.g., starting at b ₆) that includes the M chosen bases using

bits to indicate the M chosen bases 610 for each layer.

In some examples, rather than indicating a sliding window (or union set) for all layers, UE 115-c may instead indicate a sliding window of length M using

bits (e.g., if the M chosen bases have continuous indices) or ΔM using

bits (e.g., if the M chosen bases do not have continuous indices) for each layer. In such examples, UE 115-c may then transmit a bitmap of length ΔM to indicate the M chosen bases 610 for each layer, or UE 115-c may transmit a combinatorial number using

bits to indicate the M chosen bases 610 for each layer (e.g., if the M chosen bases do not have continuous indices) .

In yet other aspects of this example, UE 115-c may be configured to choose a different number of bases for different layers, and UE 115-c may be configured to choose different bases for different layers. In such aspects, base station 105-c may transmit an indication to UE 115-c of the number of bases to report for each layer (e.g., for rank indication = R, the rth layer feedbacks M _r bases, 1≤r≤R) . Thus, if one or more M _r chosen bases to be reported for all layers have continuous indices (not shown) , UE 115-c may transmit an indication of a starting index of a sliding window of length M _r indicating the M _r chosen bases in the set of bases 615 using

bits for a particular layer (e.g., where

bits may be used to indicate the bases for all R layers) . Alternatively, if one or more M _r chosen bases to be reported for all layers do not have continuous indices, UE 115-c may transmit an indication of a starting index of a sliding window of length ΔM including the M _r chosen bases in the set of bases 615 using

bits for a particular layer. UE 115-c may then transmit a bitmap of length ΔM to indicate the M chosen bases 610 for each layer (e.g., where

) bits may be used to indicate the bases for all R layers) , or UE 115-c may transmit a combinatorial number using

bits to indicate the M chosen bases 610 for each layer (e.g., where

) bits may be used to indicate the bases for all R layers) . In some cases, the value of ΔM may be different for different layers (e.g., ΔM _r) .

In some examples, rather than indicating a sliding window for each layer, UE 115-c may instead indicate a sliding window (or union set) of length ΔM using

bits for all layers. In such examples, UE 115-c may then transmit a bitmap of length ΔM to indicate the M _r chosen bases 610 for each layer (e.g., where

bits may be used to indicate the bases for all R layers) , or UE 115-c may transmit a combinatorial number using

bits to indicate the M _r chosen bases 610 for each layer (where

bits may be used to indicate the bases for all R layers) .

FIG. 7 illustrates an example of sliding windows 700 used to indicate selected bases in accordance with aspects of the present disclosure. It is to be understood that the parameters described herein may be fixed, determined by the network or a base station 105 (e.g., and indicated to a UE 115 in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message) , or determined by a UE 115 (e.g., and indicated to a base station 105) . In example 700-a, a base station 105 may transmit a control message to a UE 115 to configure the UE 115 with 16 bases (i.e., N ₃=16) from which the UE 115 may select bases to represent a preferred beam for communicating on each of three layers (i.e., rank indication = 3) . Further, the base station 105 may configure the UE 115 to select a first number of bases (M ₁=4) from a first range of bases (ΔM ₁=6) for a first layer 705-a, a second number of bases (M ₂=4) from a second range of bases ( (ΔM ₂=6) for a second layer 705-b, and a third number of bases (M ₃=4) from a third range of bases (ΔM ₃=6) for a third layer 705-c.

Accordingly, in example 700-a, for a first layer 705-a, the UE 115 may use

bits to indicate the starting index of potential bases. The UE 115 may then use a 6-bit bitmap to indicate the selected bases for the first layer 705-a, or the UE 115 may use a

combinatorial number to indicate the selected bases for the first layer 705-a. Similarly, for a second layer 705-b, the UE 115 may use

bits to indicate the starting index of potential bases. The UE 115 may then use a 5-bit bitmap to indicate the selected bases for the second layer 705-b, or the UE 115 may use a

combinatorial number to indicate the selected bases for the second layer 705-b. Further, for a third layer 705-c, the UE 115 may use

bits to indicate the starting index of potential bases. The UE 115 may then use a 4-bit bitmap to indicate the selected bases for the third layer 705-c, or the UE 115 may use a

combinatorial number to indicate the selected bases for the third layer 705-c. Thus, the overall overhead for bases selection may be 4×3+6+5+4=27 bits if bitmaps are used to indicate the selected bases and 4×3+4×2+3=23 bits if combinatorial numbers are used to indicate the selected bases.

In example 700-b, a base station 105 may also transmit a control message to a UE 115 to configure the UE 115 with 16 bases (i.e., N ₃=16) from which the UE 115 may select bases to represent a preferred beam for communicating on each of three layers (i.e., rank indication = 3) . Further, the base station 105 may configure the UE 115 to select a first number of bases (M ₁=4) for a first layer 710-a, a second number of bases (M ₂=3) for a second layer 710-b, and a third number of bases (M ₃=2) for a third layer 710-c all from a single range of bases (ΔM =10) . Accordingly, in example 700-b, UE 115 may use

bits to indicate the starting index of a sliding window (or union set) including potential bases for reporting to a base station 105. The UE 115 may then use 3 additional bitmaps each with a length of 10 bits to indicate the bases selected for each layer 710 (i.e., the layer-specific bases selections) , or the UE 115 may use 3 additional combinatorial numbers to indicate bases selected for each layer 710 (i.e., the layer-specific bases selections) , each combinatorial number having a size of

bits,

bits, and

bits respectively. Thus, the overall overhead for bases selection may be 3+3×10=33 bits if bitmaps are used to indicate the selected bases and 3+8+7+6=24 bits if combinatorial numbers are used to indicate the selected bases.

It is to be understood that the above techniques for reporting selected bases using bitmaps, combinatorial numbers, and sliding windows may be combined in various ways. Further, the sliding windows described herein may be circular shifted sliding windows, where a UE 115 may use

bits to indicate the starting index of the sliding window such that the sliding window may span a subset of a set of bases that includes a last base in the set and a first base in the set (i.e., the sliding window may wrap around or the starting index of the sliding window may be greater than the ending index of the sliding window) . Alternatively, the sliding windows described herein may be non-circular shifted sliding windows (i.e., the sliding windows may not wrap around, or the starting index of a sliding window may not be greater than the ending index of the sliding window) .

In some cases, since the layer-specific sliding window lengths may depend on a rank indication, and different rank indications may have different amounts of sliding window lengths, the payload for indicating a sliding window may be variable (e.g., which may not be appropriate for transmission in a first part of UCI) , and there may be redundant sliding window lengths when the rank indication is small. Accordingly, in such cases, a UE 115 may transmit a sliding window combination index identified from a set of sliding window combinations, where the each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator, and the set of sliding window combinations (e.g., a table of different combinations of sliding window lengths) may be predefined and/or configured by a base station 105 before transmitting. Accordingly, different rank indications may be associated with different groups of combinations, and a UE 115 may select a combination index from a table for reporting.

Further, the sliding window length for all layers or for each layer (i.e., ΔM or ΔM _r) may be derived by a UE 115 and reported to a base station 105 (e.g., the UE 115 may report the sliding window length in a first part of UCI and feedback other payloads in a second part of UCI) . In addition, if a UE 115 is configured to determine the number of bases to select for a layer, and the layer-specific bitmaps and/or combinatorial numbers to indicate layer-specific bases selections are to be sent in a second part of UCI, the UE 115 may report the explicit number of bases to be selected for the layer in the first part of the UCI to a base station 105 such that the base station 105 may be able to determine the payload size in the second part of the UCI.

In some aspects, the payload related to a first layer (e.g., used for bases selection or coefficient selection or quantization) may be transmitted in a first part of UCI. In such aspects, for layer-common bases selection, a base station 105 may indicate to a UE 115 the compressed number of bases (M) to be reported by the UE 115 and the compressed number of coefficients (K ₀) to be reported by the UE 115 for the first layer (e.g., since the rank-1 transmission may be a bottom-line transmission) . Alternatively, for layer-specific bases selection, a base station 105 may indicate to a UE 115 the compressed number of bases ( _r) to be reported by the UE 115, the compressed number of coefficients (K ₀) to be reported by the UE 115, and/or the range of bases from which the UE 115 is to select bases (ΔM or ΔM _r) for the first layer (e.g., regardless of the value of the rank indication, such that the overhead or the payload of the second part of UCI may be known by the base station 105) . Further, the indications of the coefficient selections (e.g., the number of bits and the techniques for reporting coefficients) may be based on the techniques described herein for reporting bases selections.

FIG. 8 shows a block diagram 800 of a device 805 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 805 may be an example of aspects of a UE 115 as described herein. The device 805 may include a receiver 810, a communications manager 815, and a transmitter 820. The device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bases selection in two-part UCI reporting, etc. ) . Information may be passed on to other components of the device 805. The receiver 810 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11. The receiver 810 may utilize a single antenna or a set of antennas.

The communications manager 815 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

The communications manager 815 may also identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

The communications manager 815 may also identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmit the bases report via the two-part uplink control information reporting process. The communications manager 815 may be an example of aspects of the communications manager 1110 described herein.

The communications manager 815, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 815, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 815, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 815, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 815, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 820 may transmit signals generated by other components of the device 805. In some examples, the transmitter 820 may be collocated with a receiver 810 in a transceiver module. For example, the transmitter 820 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11. The transmitter 820 may utilize a single antenna or a set of antennas.

FIG. 9 shows a block diagram 900 of a device 905 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 905 may be an example of aspects of a device 805, or a UE 115 as described herein. The device 905 may include a receiver 910, a communications manager 915, and a transmitter 935. The device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bases selection in two-part UCI reporting, etc. ) . Information may be passed on to other components of the device 905. The receiver 910 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11. The receiver 910 may utilize a single antenna or a set of antennas.

The communications manager 915 may be an example of aspects of the communications manager 815 as described herein. The communications manager 915 may include a beam manager 920, a bases reporting manager 925, and an UCI manager 930. The communications manager 915 may be an example of aspects of the communications manager 1110 described herein.

The beam manager 920 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The bases reporting manager 925 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process and generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases. The UCI manager 930 may transmit the bases report via the two-part uplink control information reporting process.

The beam manager 920 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The bases reporting manager 925 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process and generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases. The UCI manager 930 may transmit the bases report via the two-part uplink control information reporting process.

The beam manager 920 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The bases reporting manager 925 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process and generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE. The UCI manager 930 may transmit the bases report via the two-part uplink control information reporting process.

The transmitter 935 may transmit signals generated by other components of the device 905. In some examples, the transmitter 935 may be collocated with a receiver 910 in a transceiver module. For example, the transmitter 935 may be an example of aspects of the transceiver 1120 described with reference to FIG. 11. The transmitter 935 may utilize a single antenna or a set of antennas.

FIG. 10 shows a block diagram 1000 of a communications manager 1005 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The communications manager 1005 may be an example of aspects of a communications manager 815, a communications manager 915, or a communications manager 1110 described herein. The communications manager 1005 may include a beam manager 1010, a bases reporting manager 1015, an UCI manager 1020, a bitmap manager 1025, a combinatorial number manager 1030, and a sliding window manager 1035. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The beam manager 1010 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. In some examples, the beam manager 1010 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases.

In some examples, the beam manager 1010 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The bases reporting manager 1015 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. In some examples, the bases reporting manager 1015 may generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

In some examples, the bases reporting manager 1015 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. In some examples, the bases reporting manager 1015 may generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases. In some examples, the bases reporting manager 1015 may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. In some examples, the bases reporting manager 1015 may generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE.

In some examples, the bases reporting manager 1015 may generate the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases. In some examples, the bases reporting manager 1015 may generate the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices. In some examples, the bases reporting manager 1015 may transmit, with the bases report, an indication of the coefficients identifying the linear combination of the set of spatial beams, where the indication is based on the generation of the bases report. In some examples, the bases reporting manager 1015 may transmit the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process. In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.

In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined. In some cases, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some cases, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some cases, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some cases, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.

In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined. In some cases, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some cases, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some cases, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some cases, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.

The UCI manager 1020 may transmit the bases report via the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the bases report via the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the bases report via the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the first stage of the bases report during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report.

In some examples, the UCI manager 1020 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage is associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report. In some examples, the UCI manager 1020 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples, the UCI manager 1020 may transmit the second stage of the bases report during the first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the first stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the second stage of the bases report during the second part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report. In some examples, the UCI manager 1020 may transmit the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE.

In some examples, the UCI manager 1020 may transmit, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE. In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report. In some examples, the UCI manager 1020 may transmit the set of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting the bases report is associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process.

In some examples, the UCI manager 1020 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report.

In some examples, the UCI manager 1020 may transmit the bitmap during a second part of the two-part uplink control information reporting process, where a number of bits used for transmitting the bases report is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the bases report during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process. In some examples, the UCI manager 1020 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

The bitmap manager 1025 may generate the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE. In some examples, the bitmap manager 1025 may generate a set of layer-specific bitmaps. In some examples, the bitmap manager 1025 may generate a set of layer-specific bitmaps, where each of the set of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer. In some examples, the bitmap manager 1025 may generate a set of layer-specific bitmaps. In some examples, the bitmap manager 1025 may generate a single bitmap that includes all of the identified transfer domain bases for each of the layers. In some examples, the bitmap manager 1025 may generate a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers.

The combinatorial number manager 1030 may generate a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples, the combinatorial number manager 1030 may generate the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE. In some examples, the combinatorial number manager 1030 may generate a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer. In some examples, the combinatorial number manager 1030 may generate a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers.

In some cases, the set of layer-specific combinatorial numbers are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station. In some cases, the combinatorial number of the first stage and the set of layer-specific combinatorial numbers of the second stage are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station. The sliding window manager 1035 may identify that each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes a range of bases indices. In some examples, the sliding window manager 1035 may generate the first stage of the bases report as one or more starting indices for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is the same for each of the ranges of bases indices.

In some examples, the sliding window manager 1035 may receive the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples, the sliding window manager 1035 may generate a starting index that is common for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may generate a different starting index for at least some of the ranges of bases indices. In some examples, the sliding window manager 1035 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is different for at least some of the ranges of bases indices. In some examples, the sliding window manager 1035 may determine, at the UE, a sliding window length for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may transmit a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.

In some examples, the sliding window manager 1035 may identify that each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes a range of bases indices. In some examples, the sliding window manager 1035 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is the same for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may generate a starting index for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may determine, at the UE, the sliding window length for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may transmit a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.

In some examples, the sliding window manager 1035 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is different for at least some of the ranges of bases indices. In some examples, the sliding window manager 1035 may , for each layer, the sliding window length is the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases. In some examples, the sliding window manager 1035 may determine, at the UE, a sliding window length for each of the ranges of bases indices. In some examples, the sliding window manager 1035 may identify that the identified transfer domain bases are represented within a sliding window that includes a range of bases indices. In some examples, the sliding window manager 1035 may identify a sliding window length for the ranges of bases indices, where the sliding window length is the same for each layer.

In some examples, the sliding window manager 1035 may generate a starting index for the sliding window, where the starting index is the same for each layer. In some examples, the sliding window manager 1035 may receive the sliding window length via a configuration from the base station. In some examples, the sliding window manager 1035 may determine, at the UE, a sliding window length for the ranges of bases indices. In some examples, the sliding window manager 1035 may transmit a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some cases, the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.

In some cases, the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window. In some cases, the set of sliding window combinations is either predefined or is received from the base station via one or more configuration messages. In some cases, the sliding window length is predetermined. In some cases, the sliding window length is the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases. In some cases, the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window. In some cases, the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.

In some cases, the set of sliding window combinations is either predefined or is received from the base station via one or more configuration messages. In some cases, each of the sliding window lengths is predetermined. In some cases, the sliding window length is predetermined. In some cases, the range of bases indices is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window. In some cases, the range of bases indices is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window. In some cases, the set of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.

FIG. 11 shows a diagram of a system 1100 including a device 1105 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 1105 may be an example of or include the components of device 805, device 905, or a UE 115 as described herein. The device 1105 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1110, an I/O controller 1115, a transceiver 1120, an antenna 1125, memory 1130, and a processor 1140. These components may be in electronic communication via one or more buses (e.g., bus 1145) .

The communications manager 1110 may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

The communications manager 1110 may also identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases, and transmit the bases report via the two-part uplink control information reporting process.

The communications manager 1110 may also identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases, identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process, generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE, and transmit the bases report via the two-part uplink control information reporting process.

The I/O controller 1115 may manage input and output signals for the device 1105. The I/O controller 1115 may also manage peripherals not integrated into the device 1105. In some cases, the I/O controller 1115 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1115 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 1115 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1115 may be implemented as part of a processor. In some cases, a user may interact with the device 1105 via the I/O controller 1115 or via hardware components controlled by the I/O controller 1115.

The transceiver 1120 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1120 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1120 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1125. However, in some cases the device may have more than one antenna 1125, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1130 may include RAM and ROM. The memory 1130 may store computer-readable, computer-executable code 1135 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1130 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1140 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1140 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1140. The processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting bases selection in two-part UCI reporting) .

The code 1135 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1135 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1135 may not be directly executable by the processor 1140 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 12 shows a block diagram 1200 of a device 1205 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 1205 may be an example of aspects of a base station 105 as described herein. The device 1205 may include a receiver 1210, a communications manager 1215, and a transmitter 1220. The device 1205 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bases selection in two-part UCI reporting, etc. ) . Information may be passed on to other components of the device 1205. The receiver 1210 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15. The receiver 1210 may utilize a single antenna or a set of antennas.

The communications manager 1215 may transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

The communications manager 1215 may also transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

The communications manager 1215 may also transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE. The communications manager 1215 may be an example of aspects of the communications manager 1510 described herein.

The communications manager 1215, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1215, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 1215, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1215, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1215, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1220 may transmit signals generated by other components of the device 1205. In some examples, the transmitter 1220 may be collocated with a receiver 1210 in a transceiver module. For example, the transmitter 1220 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15. The transmitter 1220 may utilize a single antenna or a set of antennas.

FIG. 13 shows a block diagram 1300 of a device 1305 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 1305 may be an example of aspects of a device 1205, or a base station 105 as described herein. The device 1305 may include a receiver 1310, a communications manager 1315, and a transmitter 1330. The device 1305 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to bases selection in two-part UCI reporting, etc. ) . Information may be passed on to other components of the device 1305. The receiver 1310 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15. The receiver 1310 may utilize a single antenna or a set of antennas.

The communications manager 1315 may be an example of aspects of the communications manager 1215 as described herein. The communications manager 1315 may include a beam manager 1320 and an UCI manager 1325. The communications manager 1315 may be an example of aspects of the communications manager 1510 described herein.

The beam manager 1320 may transmit one or more transmissions to a UE via a set of spatial transmit beams. The UCI manager 1325 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

The beam manager 1320 may transmit one or more transmissions to a UE via a set of spatial transmit beams. The UCI manager 1325 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

The beam manager 1320 may transmit one or more transmissions to a UE via a set of spatial transmit beams. The UCI manager 1325 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

The transmitter 1330 may transmit signals generated by other components of the device 1305. In some examples, the transmitter 1330 may be collocated with a receiver 1310 in a transceiver module. For example, the transmitter 1330 may be an example of aspects of the transceiver 1520 described with reference to FIG. 15. The transmitter 1330 may utilize a single antenna or a set of antennas.

FIG. 14 shows a block diagram 1400 of a communications manager 1405 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The communications manager 1405 may be an example of aspects of a communications manager 1215, a communications manager 1315, or a communications manager 1510 described herein. The communications manager 1405 may include a beam manager 1410, an UCI manager 1415, a bases report manager 1420, a bitmap manager 1425, a combinatorial number manager 1430, a sliding window manager 1435, and a coefficients manager 1440. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The beam manager 1410 may transmit one or more transmissions to a UE via a set of spatial transmit beams. In some examples, the beam manager 1410 may transmit one or more transmissions to a UE via a set of spatial transmit beams. In some examples, the beam manager 1410 may transmit one or more transmissions to a UE via a set of spatial transmit beams. The UCI manager 1415 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

In some examples, the UCI manager 1415 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

In some examples, the UCI manager 1415 may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. In some cases, a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain. The bases report manager 1420 may receive the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE. In some examples, the bases report manager 1420 may receive the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases.

In some examples, the bases report manager 1420 may receive the first stage of the bases report during a first part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report. In some examples, the bases report manager 1420 may receive both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for both the first stage and the second stage is associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples, the bases report manager 1420 may transmit to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined. In some examples, the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples, the bases report manager 1420 may receive the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE. In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report. In some examples, the bases report manager 1420 may receive both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.

In some examples, the bases report manager 1420 may receive the first stage of the bases report as one or more starting indices for corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices. In some examples, the bases report manager 1420 may receive the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices. In some examples, the bases report manager 1420 may receive the second stage of the bases report during the first part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive the first stage of the bases report during a second part of the two-part uplink control information reporting process.

In some examples, the bases report manager 1420 may receive the second stage of the bases report during the second part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report. In some examples, the bases report manager 1420 may receive the bases report during a second part of the two-part uplink control information reporting process, where a number of bits used for both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.

In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE. In some examples, the bases report manager 1420 may receive, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE. In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report. In some examples, the bases report manager 1420 may transmit to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined. In some examples, the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.

In some examples, the bases report manager 1420 may transmit both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report.

In some examples, the bases report manager 1420 may receive the bitmap during a second part of the two-part uplink control information reporting process, where a number of bits used for the bases report is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may transmit to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined. In some examples, the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples, the bases report manager 1420 may receive the bases report during a first part of the two-part uplink control information reporting process. In some examples, the bases report manager 1420 may receive both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.

In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined. In some cases, at least some of the layers include different layer-specific subsets of the identified transfer domain bases. In some cases, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some cases, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some cases, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined. In some cases, at least some of the layers include different layer-specific subsets of the identified transfer domain bases.

In some cases, at least some of the layers include the same layer-specific subsets of the identified transfer domain bases. In some cases, each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases. In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined. In some cases, at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases. In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined. In some cases, a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.

The bitmap manager 1425 may receive a set of layer-specific bitmaps. In some examples, the bitmap manager 1425 may receive a set of layer-specific bitmaps, where each of the set of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer. In some examples, the bitmap manager 1425 may receive a set of layer-specific bitmaps. In some examples, the bitmap manager 1425 may receive the set of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, where a number of bits used for the bases report is associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process. In some examples, the bitmap manager 1425 may receive a single bitmap that includes all of the identified transfer domain bases for each of the layers. In some examples, the bitmap manager 1425 may receive a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers.

The combinatorial number manager 1430 may receive a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer. In some examples, the combinatorial number manager 1430 may receive a set of layer-specific combinatorial numbers, where each of the set of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer. In some examples, the combinatorial number manager 1430 may receive a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers. In some cases, the set of layer-specific combinatorial numbers are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station. In some cases, the combinatorial number of the first stage and the set of layer-specific combinatorial numbers of the second stage are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.

The sliding window manager 1435 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is the same for each of the ranges of bases indices. In some examples, the sliding window manager 1435 may transmit the sliding window length for each of the ranges of bases indices via a configuration from the base station. In some examples, the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples, the sliding window manager 1435 may receive a starting index that is common for each of the ranges of bases indices. In some examples, the sliding window manager 1435 may receive a different starting index for at least some of the ranges of bases indices. In some examples, the sliding window manager 1435 may identify a sliding window length for each of the ranges of bases indices, where the sliding window length is different for at least some of the ranges of bases indices. In some examples, the sliding window manager 1435 may receive one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process.

In some examples, the sliding window manager 1435 may receive a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples, the sliding window manager 1435 may receive a starting index for each of corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices, where a sliding window length is the same for each of the ranges of bases indices. In some examples, the sliding window manager 1435 may receive the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.

In some examples, the sliding window manager 1435 may receive one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process. In some examples, the sliding window manager 1435 may receive both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process. In some examples, the sliding window manager 1435 may receive a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some examples, the sliding window manager 1435 may receive a starting index for each of corresponding ranges of bases indices, where each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices, where a sliding window length is different for each of the ranges of bases indices.

In some examples, the sliding window manager 1435 may, for each layer, the sliding window length is the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases. In some examples, the sliding window manager 1435 may determine, at the UE, a sliding window length for each of the ranges of bases indices. In some examples, the sliding window manager 1435 may receive a starting index for a range of bases indices, where the identified transfer domain bases are represented within a sliding window that includes the range of bases indices, where a sliding window length is the same for each layer. In some examples, the sliding window manager 1435 may transmit the sliding window length via a configuration from the base station. In some examples, the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message. In some examples, the sliding window manager 1435 may receive a sliding window length for the ranges of bases indices, as determined at the UE, during a first part of the two-part uplink control information reporting process.

In some examples, the sliding window manager 1435 may receive a sliding window combination index identified from a set of sliding window combinations, where each of the set of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator. In some cases, the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window. In some cases, the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window. In some cases, the set of sliding window combinations is either predefined or is configured by the base station via one or more configuration messages.

In some cases, the sliding window length is predetermined. In some cases, the sliding window length is the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases. In some cases, the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window. In some cases, the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window. In some cases, the set of sliding window combinations is either predefined or is transmitted by the base station via one or more configuration messages. In some cases, each of the sliding window lengths is predetermined. In some cases, the set of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.

In some cases, the sliding window length is predetermined. In some cases, the range of bases indices is a circular-shifted sliding window whose circulation is associated with the range of bases indices, where a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window. In some cases, the range of bases indices is a non-circular-shifted sliding window, where a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window. In some cases, the set of sliding window combinations is either predefined or is received from the base station via one or more configuration messages. The coefficients manager 1440 may receive, with the bases report, an indication of the coefficients identifying the linear combination of the set of spatial beams, where the indication is based on the generation of the bases report.

FIG. 15 shows a diagram of a system 1500 including a device 1505 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The device 1505 may be an example of or include the components of device 1205, device 1305, or a base station 105 as described herein. The device 1505 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1510, a network communications manager 1515, a transceiver 1520, an antenna 1525, memory 1530, a processor 1540, and an inter-station communications manager 1545. These components may be in electronic communication via one or more buses (e.g., bus 1550) .

The communications manager 1510 may transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.

The communications manager 1510 may also transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.

The communications manager 1510 may also transmit one or more transmissions to a UE via a set of spatial transmit beams and receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.

The network communications manager 1515 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1515 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1520 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1520 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1520 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1525. However, in some cases the device may have more than one antenna 1525, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1530 may include RAM, ROM, or a combination thereof. The memory 1530 may store computer-readable code 1535 including instructions that, when executed by a processor (e.g., the processor 1540) cause the device to perform various functions described herein. In some cases, the memory 1530 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1540 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1540 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1540. The processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1530) to cause the device 1505 to perform various functions (e.g., functions or tasks supporting bases selection in two-part UCI reporting) .

The inter-station communications manager 1545 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1545 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1545 may provide an X2 interface within an LTE/LTE-Awireless communication network technology to provide communication between base stations 105.

The code 1535 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1535 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1535 may not be directly executable by the processor 1540 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 16 shows a flowchart illustrating a method 1600 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 8 through 11. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1605, the UE may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a beam manager as described with reference to FIGs. 8 through 11.

At 1610, the UE may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1615, the UE may generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1620, the UE may transmit the bases report via the two-part uplink control information reporting process. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by an UCI manager as described with reference to FIGs. 8 through 11.

FIG. 17 shows a flowchart illustrating a method 1700 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 8 through 11. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1705, the UE may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a beam manager as described with reference to FIGs. 8 through 11.

At 1710, the UE may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1715, the UE may generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1720, the UE may transmit the bases report via the two-part uplink control information reporting process. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by an UCI manager as described with reference to FIGs. 8 through 11.

FIG. 18 shows a flowchart illustrating a method 1800 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 1800 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1800 may be performed by a communications manager as described with reference to FIGs. 8 through 11. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1805, the UE may identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of a set of spatial beams, where coefficients identifying the linear combination of the set of spatial beams are based on a set of transfer domain bases. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a beam manager as described with reference to FIGs. 8 through 11.

At 1810, the UE may identify that the set of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1815, the UE may generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by a bases reporting manager as described with reference to FIGs. 8 through 11.

At 1820, the UE may transmit the bases report via the two-part uplink control information reporting process. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by an UCI manager as described with reference to FIGs. 8 through 11.

FIG. 19 shows a flowchart illustrating a method 1900 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 1900 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1900 may be performed by a communications manager as described with reference to FIGs. 12 through 15. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1905, the base station may transmit one or more transmissions to a UE via a set of spatial transmit beams. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a beam manager as described with reference to FIGs. 12 through 15.

At 1910, the base station may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by an UCI manager as described with reference to FIGs. 12 through 15.

FIG. 20 shows a flowchart illustrating a method 2000 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 2000 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2000 may be performed by a communications manager as described with reference to FIGs. 12 through 15. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 2005, the base station may transmit one or more transmissions to a UE via a set of spatial transmit beams. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed by a beam manager as described with reference to FIGs. 12 through 15.

At 2010, the base station may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of layer-specific subsets of the identified transfer domain bases. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed by an UCI manager as described with reference to FIGs. 12 through 15.

FIG. 21 shows a flowchart illustrating a method 2100 that supports bases selection in two-part UCI reporting in accordance with aspects of the present disclosure. The operations of method 2100 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2100 may be performed by a communications manager as described with reference to FIGs. 12 through 15. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 2105, the base station may transmit one or more transmissions to a UE via a set of spatial transmit beams. The operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be performed by a beam manager as described with reference to FIGs. 12 through 15.

At 2110, the base station may receive, via a two-part uplink control information reporting process, a bases report identifying a set of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, where the preferred spatial transmit beams for a layer are based on a linear combination of at least some of the set of spatial transmit beams, and coefficients identifying the linear combination of the set of spatial transmit beams are based on the set of transfer domain bases, and where the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE. The operations of 2110 may be performed according to the methods described herein. In some examples, aspects of the operations of 2110 may be performed by an UCI manager as described with reference to FIGs. 12 through 15.

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.

Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single carrier frequency division multiple access (SC-FDMA) , and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .

An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS) . LTE, LTE-A, and LTE-A Pro are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned herein as well as other systems and radio technologies. While 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 applications.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell may be associated with a lower-powered base station, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells, and may also support communications using one or multiple component carriers.

The wireless communications systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

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 modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, 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 conventional 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) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on 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 can 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 place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (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 can be used to carry or store desired program code means in the form of instructions or data structures and that can 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 medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

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 exemplary 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. ”

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 “exemplary” 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, well-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 skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled 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 method for wireless communication at a user equipment (UE) , comprising:

identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generating a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases; and

transmitting the bases report via the two-part uplink control information reporting process.
The method of claim 1, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 1, wherein generating the bases report comprises:

generating the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE; and

generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases.
The method of claim 3, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific bitmaps.
The method of claim 3, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer.
The method of claim 5, wherein the plurality of layer-specific combinatorial numbers are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.
The method of claim 3, wherein transmitting the bases report comprises:

transmitting the first stage of the bases report during a first part of the two-part uplink control information reporting process; and

transmitting the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 3, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for transmitting both the first stage and the second stage is associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 3, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 3, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 3, wherein at least some of the layers include the same layer-specific subsets of the identified transfer domain bases.
The method of claim 1, wherein generating the bases report comprises:

generating the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE; and

generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases.
The method of claim 12, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific bitmaps.
The method of claim 12, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer.
The method of claim 14, wherein the combinatorial number of the first stage and the plurality of layer-specific combinatorial numbers of the second stage are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.
The method of claim 12, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for transmitting both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 12, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 12, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 12, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 1, wherein generating the bases report comprises:

identifying that each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes a range of bases indices;

generating the first stage of the bases report as one or more starting indices for each of the ranges of bases indices; and

generating the second stage of the bases report to identify the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices.
The method of claim 20, further comprising:

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is the same for each of the ranges of bases indices.
The method of claim 21, further comprising:

receiving the sliding window length for each of the ranges of bases indices via a configuration from the base station.
The method of claim 21, wherein generating the first stage of the bases report comprises:

generating a starting index that is common for each of the ranges of bases indices.
The method of claim 21, wherein generating the first stage of the bases report comprises:

generating a different starting index for at least some of the ranges of bases indices.
The method of claim 21, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific bitmaps, wherein each of the plurality of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.
The method of claim 21, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer.
The method of claim 21, wherein transmitting the bases report comprises:

transmitting the first stage of the bases report during a first part of the two-part uplink control information reporting process; and

transmitting the second stage of the bases report during the first part of the two-part uplink control information reporting process.
The method of claim 21, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 21, wherein each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.
The method of claim 21, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 20, further comprising:

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is different for at least some of the ranges of bases indices.
The method of claim 31, further comprising:

receiving the sliding window length for each of the ranges of bases indices via a configuration from the base station.
The method of claim 31, wherein generating the first stage of the bases report comprises:

generating a starting index that is common for each of the ranges of bases indices.
The method of claim 31, wherein generating the first stage of the bases report comprises:

generating a different starting index for at least some of the ranges of bases indices.
The method of claim 31, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific bitmaps, wherein each of the plurality of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.
The method of claim 31, wherein generating the second stage of the bases report comprises:

generating a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer.
The method of claim 31, wherein transmitting the bases report comprises:

transmitting the first stage of the bases report during a second part of the two-part uplink control information reporting process; and

transmitting the second stage of the bases report during the second part of the two-part uplink control information reporting process.
The method of claim 31, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 31, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 31, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 20, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 20, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 20, further comprising:

determining, at the UE, a sliding window length for each of the ranges of bases indices.
The method of claim 43, wherein transmitting the bases report comprises:

transmitting the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 44, wherein transmitting the sliding window lengths comprises:

transmitting a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 45, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
The method of claim 20, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report; and

transmitting the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for transmitting both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 1, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE; and

transmitting, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE.
The method of claim 1, further comprising:

transmitting, with the bases report, an indication of the coefficients identifying the linear combination of the plurality of spatial beams, wherein the indication is based at least in part on the generation of the bases report.
A method for wireless communication at a user equipment (UE) , comprising:

identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases; and

transmitting the bases report via the two-part uplink control information reporting process.
The method of claim 50, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 50, wherein generating the bases report comprises:

generating a plurality of layer-specific bitmaps.
The method of claim 52, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report; and

transmitting the plurality of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, wherein a number of bits used for transmitting the bases report is associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 52, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 52, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 52, wherein at least some of the layers include the same layer-specific subsets of the identified transfer domain bases.
The method of claim 50, wherein generating the bases report comprises:

identifying that each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes a range of bases indices;

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is the same for each of the ranges of bases indices; and

generating a starting index for each of the ranges of bases indices.
The method of claim 57, wherein the sliding window length is predetermined.
The method of claim 57, wherein the sliding window length is the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases.
The method of claim 57, wherein transmitting the bases report comprises:

transmitting the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.
The method of claim 57, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 57, wherein each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.
The method of claim 57, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 57, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 57, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 57, wherein identifying the sliding window length for each of the ranges of bases indices comprises:

determining, at the UE, the sliding window length for each of the ranges of bases indices.
The method of claim 66, wherein transmitting the bases report comprises:

transmitting the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 67, wherein transmitting the sliding window length comprises:

transmitting a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 68, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
The method of claim 50, wherein generating the bases report comprises:

identifying that each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes a range of bases indices;

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is different for at least some of the ranges of bases indices; and

generating a starting index for each of the ranges of bases indices.
The method of claim 70, wherein each of the sliding window lengths is predetermined.
The method of claim 70, wherein, for each layer, the sliding window length is the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases.
The method of claim 70, wherein transmitting the bases report comprises:

transmitting the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.
The method of claim 70, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 70, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 70, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 70, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 70, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 70, wherein identifying the sliding window length for each of the ranges of bases indices comprises:

determining, at the UE, a sliding window length for each of the ranges of bases indices.
The method of claim 79, wherein transmitting the bases report comprises:

transmitting the sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 80, wherein transmitting the sliding window lengths comprises:

transmitting a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 81, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
A method for wireless communication at a user equipment (UE) , comprising:

identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE; and

transmitting the bases report via the two-part uplink control information reporting process.
The method of claim 83, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 83, wherein generating the bases report comprises:

generating a single bitmap that includes all of the identified transfer domain bases for each of the layers.
The method of claim 85, wherein transmitting the bases report comprises:

transmitting, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report; and

transmitting the bitmap during a second part of the two-part uplink control information reporting process, wherein a number of bits used for transmitting the bases report is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 85, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 83, wherein generating the bases report comprises:

identifying that the identified transfer domain bases are represented within a sliding window that includes a range of bases indices;

identifying a sliding window length for the ranges of bases indices, wherein the sliding window length is the same for each layer; and

generating a starting index for the sliding window, wherein the starting index is the same for each layer.
The method of claim 88, wherein the sliding window length is predetermined.
The method of claim 88, wherein identifying the sliding window length comprises:

receiving the sliding window length via a configuration from the base station.
The method of claim 88, further comprising:

generating a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers.
The method of claim 88, further comprising:

generating a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers.
The method of claim 88, wherein transmitting the bases report comprises:

transmitting the bases report during a first part of the two-part uplink control information reporting process.
The method of claim 88, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 88, wherein the range of bases indices is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 88, wherein the range of bases indices is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 88, wherein identifying the sliding window length for the ranges of bases indices comprises:

determining, at the UE, a sliding window length for the ranges of bases indices.
The method of claim 97, wherein transmitting the bases report comprises:

transmitting the sliding window length, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 98, wherein transmitting the sliding window length comprises:

transmitting a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 99, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
A method for wireless communication at a base station, comprising:

transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on a plurality of transfer domain bases, and wherein the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.
The method of claim 101, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 101, wherein receiving the bases report comprises:

receiving the first stage of the bases report as a bitmap that includes a union set of the identified transfer domain bases for all of the layers supported by the UE; and

receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases.
The method of claim 103, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific bitmaps.
The method of claim 103, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer.
The method of claim 105, wherein the plurality of layer-specific combinatorial numbers are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.
The method of claim 103, wherein receiving the bases report comprises:

receiving the first stage of the bases report during a first part of the two-part uplink control information reporting process; and

receiving the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 103, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the first stage of the bases report; and

receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for both the first stage and the second stage is associated with the number of the transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 103, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 110, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 103, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 103, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 103, wherein at least some of the layers include the same layer-specific subsets of the identified transfer domain bases.
The method of claim 101, wherein receiving the bases report comprises:

receiving the first stage of the bases report as a combinatorial number representing a union set of the identified transfer domain bases for all of the layers supported by the UE; and

receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases.
The method of claim 114, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific bitmaps.
The method of claim 114, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases for a corresponding layer.
The method of claim 116, wherein the combinatorial number of the first stage and the plurality of layer-specific combinatorial numbers of the second stage are based on at least one of a look-up table common to both the UE and the base station or a searching algorithm common to both the UE and the base station.
The method of claim 114, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the first stage of the bases report; and

receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the first stage and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 114, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 119, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 114, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 114, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 114, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 101, wherein receiving the bases report comprises:

receiving the first stage of the bases report as one or more starting indices for corresponding ranges of bases indices, wherein each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices; and

receiving the second stage of the bases report identifying the layer-specific subsets of the identified transfer domain bases within each of the ranges of bases indices.
The method of claim 124, further comprising:

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is the same for each of the ranges of bases indices.
The method of claim 125, further comprising:

transmitting the sliding window length for each of the ranges of bases indices via a configuration from the base station.
The method of claim 126, wherein the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 125, wherein receiving the first stage of the bases report comprises:

receiving a starting index that is common for each of the ranges of bases indices.
The method of claim 125, wherein receiving the first stage of the bases report comprises:

receiving a different starting index for at least some of the ranges of bases indices.
The method of claim 125, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific bitmaps, wherein each of the plurality of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.
The method of claim 125, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer.
The method of claim 125, wherein receiving the bases report comprises:

receiving the first stage of the bases report during a first part of the two-part uplink control information reporting process; and

receiving the second stage of the bases report during the first part of the two-part uplink control information reporting process.
The method of claim 125, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 133, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 125, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 125, wherein each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.
The method of claim 125, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 124, further comprising:

identifying a sliding window length for each of the ranges of bases indices, wherein the sliding window length is different for at least some of the ranges of bases indices.
The method of claim 138, further comprising:

transmitting the sliding window length for each of the ranges of bases indices via a configuration from the base station.
The method of claim 139, wherein the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 138, wherein receiving the first stage of the bases report comprises:

receiving a starting index that is common for each of the ranges of bases indices.
The method of claim 138, wherein receiving the first stage of the bases report comprises:

receiving a different starting index for at least some of the ranges of bases indices.
The method of claim 138, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific bitmaps, wherein each of the plurality of layer-specific bitmaps identifies the transfer domain bases within the range of bases indices for a respective layer.
The method of claim 138, wherein receiving the second stage of the bases report comprises:

receiving a plurality of layer-specific combinatorial numbers, wherein each of the plurality of layer-specific combinatorial numbers represents a combination of transfer domain bases within the range of bases indices for a respective layer.
The method of claim 138, wherein receiving the bases report comprises:

receiving the first stage of the bases report during a second part of the two-part uplink control information reporting process; and

receiving the second stage of the bases report during the second part of the two-part uplink control information reporting process.
The method of claim 138, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 146, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 138, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 138, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 138, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 124, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 124, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 124, wherein receiving the bases report comprises:

receiving one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 153, wherein receiving the sliding window lengths comprises:

receiving a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 154, wherein the plurality of sliding window combinations is either predefined or is configured by the base station via one or more configuration messages.
The method of claim 124, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report; and

receiving the bases report during a second part of the two-part uplink control information reporting process, wherein a number of bits used for both the first stage and the second stage is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 101, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, a portion of the bases report pertaining to a first layer of the one or more layers supported by the UE; and

receiving, during a second part of the two-part uplink control information reporting process, a remaining portion of the bases report pertaining to additional layers of the one or more layers supported by the UE.
The method of claim 101, further comprising:

receiving, with the bases report, an indication of the coefficients identifying the linear combination of the plurality of spatial beams, wherein the indication is based at least in part on the generation of the bases report.
A method for wireless communication at a base station, comprising:

transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on a plurality of transfer domain bases, and wherein the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.
The method of claim 159, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 159, wherein receiving the bases report comprises:

receiving a plurality of layer-specific bitmaps.
The method of claim 161, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the transfer domain bases included in the bases report; and

receiving the plurality of layer-specific bitmaps during a second part of the two-part uplink control information reporting process, wherein a number of bits used for the bases report is associated with the number of the transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 161, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 163, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 161, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 161, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 161, wherein at least some of the layers include the same layer-specific subsets of the identified transfer domain bases.
The method of claim 159, wherein receiving the bases report comprises:

receiving a starting index for each of corresponding ranges of bases indices, wherein each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices, wherein a sliding window length is the same for each of the ranges of bases indices.
The method of claim 168, wherein the sliding window length is predetermined.
The method of claim 168, wherein the sliding window length is the same as a number of transfer domain bases within each layer-specific subset of the identified transfer domain bases.
The method of claim 168, wherein receiving the bases report comprises:

receiving the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.
The method of claim 168, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 172, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 168, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 168, wherein each layer-specific subset of the identified transfer domain bases includes a same number of transfer domain bases.
The method of claim 168, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 168, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 168, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 168, wherein receiving the bases report comprises:

receiving one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 179, wherein receiving the sliding window length comprises:

receiving a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 180, wherein the plurality of sliding window combinations is either predefined or is transmitted by the base station via one or more configuration messages.
The method of claim 159, wherein receiving the bases report comprises:

receiving a starting index for each of corresponding ranges of bases indices, wherein each layer-specific subset of the identified transfer domain bases is represented within a sliding window that includes the respective range of bases indices, wherein a sliding window length is different for each of the ranges of bases indices.
The method of claim 182, wherein each of the sliding window lengths is predetermined.
The method of claim 182, wherein, for each layer, the sliding window length is the same as a number of transfer domain bases within a respective layer-specific subset of the identified transfer domain bases.
The method of claim 182, wherein receiving the bases report comprises:

receiving the starting indices for each of the ranges of bases indices during a first part of the two-part uplink control information reporting process.
The method of claim 182, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 182, wherein at least some of the layer-specific subsets of the identified transfer domain bases include different numbers of transfer domain bases.
The method of claim 182, wherein at least some of the layers include different layer-specific subsets of the identified transfer domain bases.
The method of claim 182, wherein the range of bases indices for at least one of the layers is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 182, wherein the range of bases indices for at least one of the layers is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 182, wherein identifying the sliding window length for each of the ranges of bases indices comprises:

determining, at the UE, a sliding window length for each of the ranges of bases indices.
The method of claim 191, wherein receiving the bases report comprises:

receiving one or more sliding window lengths, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

transmitting both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 192, wherein receiving the sliding window lengths comprises:

receiving a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 193, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
A method for wireless communication at a base station, comprising:

transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on a plurality of transfer domain bases, and wherein the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.
The method of claim 195, wherein a transfer domain of the transfer domain bases is based on one or more of a Discrete Fourier Transform (DFT) bases domain or a Discrete Cosine Transfer (DCT) bases domain.
The method of claim 195, wherein receiving the bases report comprises:

receiving a single bitmap that includes all of the identified transfer domain bases for each of the layers.
The method of claim 197, wherein receiving the bases report comprises:

receiving, during a first part of the two-part uplink control information reporting process, an indication of a number of the identified transfer domain bases included in the bases report; and

receiving the bitmap during a second part of the two-part uplink control information reporting process, wherein a number of bits used for the bases report is associated with the number of the identified transfer domain bases included in the bases report and indicated in the first part of the two-part uplink control information reporting process.
The method of claim 197, further comprising:

transmitting to the UE an indication of a quantity of transfer domain bases from which the identified transfer domain bases are to be determined.
The method of claim 199, wherein the indication is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 197, wherein a quantity of transfer domain bases from which the identified transfer domain bases are to be determined is predetermined.
The method of claim 195, wherein receiving the bases report comprises:

receiving a starting index for a range of bases indices, wherein the identified transfer domain bases are represented within a sliding window that includes the range of bases indices, wherein a sliding window length is the same for each layer.
The method of claim 202, wherein the sliding window length is predetermined.
The method of claim 202, further comprising:

transmitting the sliding window length via a configuration from the base station.
The method of claim 204, wherein the sliding window length is transmitted in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE) , or a downlink control information (DCI) message.
The method of claim 202, wherein receiving the bases report comprises:

receiving a bitmap that identifies the transfer domain bases within the range of bases indices for each of the layers.
The method of claim 202, wherein receiving the bases report comprises:

receiving a combinatorial number representing a combination of transfer domain bases within the range of bases indices for each of the layers.
The method of claim 202, wherein receiving the bases report comprises:

receiving the bases report during a first part of the two-part uplink control information reporting process.
The method of claim 202, wherein a quantity of transfer domain bases from which the identified transfer domain bases are determined is based on a configuration received from the base station or is predetermined.
The method of claim 202, wherein the range of bases indices is a circular-shifted sliding window whose circulation is associated with the range of bases indices, wherein a starting index of the circular-shifted sliding window is greater than an ending index of the circular-shifted sliding window.
The method of claim 202, wherein the range of bases indices is a non-circular-shifted sliding window, wherein a starting index of the non-circular-shifted sliding window is less than an ending index of the non-circular-shifted sliding window.
The method of claim 202, wherein receiving the bases report comprises:

receiving a sliding window length for the ranges of bases indices, as determined at the UE, during a first part of the two-part uplink control information reporting process; and

receiving both the first stage of the bases report and the second stage of the bases report during a second part of the two-part uplink control information reporting process.
The method of claim 212, wherein receiving the sliding window length comprises:

receiving a sliding window combination index identified from a plurality of sliding window combinations, wherein each of the plurality of sliding window combinations identifies sliding window lengths associated with different layers for an identified rank indicator.
The method of claim 213, wherein the plurality of sliding window combinations is either predefined or is received from the base station via one or more configuration messages.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases; and

transmit the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases; and

transmit the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE; and

transmit the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

means for identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

means for generating a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases; and

means for transmitting the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

means for identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

means for generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases; and

means for transmitting the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for identifying, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

means for identifying that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

means for generating a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE; and

means for transmitting the bases report via the two-part uplink control information reporting process.
An apparatus for wireless communication at a base station, comprising:

means for transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

means for receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.
An apparatus for wireless communication at a base station, comprising:

means for transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

means for receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.
An apparatus for wireless communication at a base station, comprising:

means for transmitting one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

means for receiving, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including a first stage associated with the identified transfer domain bases for all layers and a second stage associated with layer-specific subsets of the identified transfer domain bases; and

transmit the bases report via the two-part uplink control information reporting process.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of layer-specific subsets of the identified transfer domain bases; and

transmit the bases report via the two-part uplink control information reporting process.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

identify, at the UE and based on receipt of one or more transmissions from a base station, one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of a plurality of spatial beams, wherein coefficients identifying the linear combination of the plurality of spatial beams are based at least in part on a plurality of transfer domain bases;

identify that the plurality of transfer domain bases corresponding to preferred spatial transmit beams for each layer are to be reported to the base station via a two-part uplink control information reporting process;

generate a bases report for reporting the identified transfer domain bases, the bases report including an identification of transfer domain bases that are common to each layer supported by the UE; and

transmit the bases report via the two-part uplink control information reporting process.
A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes a first stage identifying transfer domain bases associated with all UE-supported layers and a second stage associated with layer-specific subsets of the identified transfer domain bases.
A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of layer-specific subsets of the identified transfer domain bases.
A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to:

transmit one or more transmissions to a user equipment (UE) via a plurality of spatial transmit beams; and

receive, via a two-part uplink control information reporting process, a bases report identifying a plurality of transfer domain bases associated with an identification of one or more preferred spatial transmit beams for communication by the base station with the UE via one or more layers supported by the UE, wherein the preferred spatial transmit beams for a layer are based at least in part on a linear combination of at least some of the plurality of spatial transmit beams, and coefficients identifying the linear combination of the plurality of spatial transmit beams are based at least in part on the plurality of transfer domain bases, and wherein the bases report includes an identification of transfer domain bases that are common to each layer supported by the UE.