Layer-Specific Feedback Period

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive channel state information (CSI) configuration from a base station, the CSI configuration indicating a first feedback reporting period for a dominant or strong spatial layer and a second feedback reporting period for a non-dominant or weak spatial layer. The UE may transmit a first CSI report for at least the dominant spatial layer according to the first feedback reporting period. The UE may transmit a second CSI report for the non-dominant spatial layer according to the second feedback reporting period. In some cases, for aperiodic reporting, the UE may be triggered by downlink control information to report CSI for the dominant spatial layer. In some cases, the CSI configuration may indicate different codebooks for the dominant spatial layer and the non-dominant spatial layer.

Description

Technical Field

[0001] The following relates to wireless communication, including layer-specific feedback cycles. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcasting, etc. These systems are capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multi-access systems include fourth-generation (4G) systems (e.g., Long Term Evolution (LTE) systems, enhanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems (which may be referred to as New Radio (NR) systems). These systems may employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), or Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multi-access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication for multiple communication devices (which may alternatively be referred to as user equipment (UE)).

[0003] A UE may provide information such as channel state information (CSI) to a base station to convey the channel quality or other metrics for a channel used for communication between the base station and the UE. The information may correspond to different spatial layers supported during beamforming communication with the base station. Techniques for reporting such information for different layers may increase overhead and signaling, which may result in inefficient use of network resources. Summary of the Invention

[0004] The described techniques relate to improved methods, systems, devices, and apparatuses that support layer-specific feedback cycles. A base station and a user equipment (UE) may communicate using beamforming communication. A transmitting device may precode data for an application and transmit the data directionally via one or more spatial layers or data streams based on the precoding. Some spatial layers may be strong spatial layers that may transmit beamforming information in the direction of the UE. Some other spatial layers may be weak spatial layers that may not be precisely directed at the UE. The UE may receive a beamforming transmission from the base station and provide feedback in response. For example, the base station may transmit a Channel State Information (CSI) Reference Signal (CSI-RS). The UE may measure the CSI-RS and send a report for the measurement to the base station.

[0005] The wireless communication system described herein supports techniques for efficient CSI reporting. For example, a UE may be configured with different periods or triggers to report CSI for dominant (e.g., strong) spatial layers and non-dominant (e.g., non-strong, or weak) spatial layers. A UE may have one or more dominant spatial layers and one or more non-dominant spatial layers. In some cases, the UE may send an indication to the base station as to which spatial layers correspond to the dominant spatial layers. In some cases, the dominant spatial layers and the non-dominant spatial layers may be configured with different codebooks or codebook types. For periodic reporting, the dominant spatial layers may have a different CSI reporting period than the non-dominant spatial layers. For example, the dominant spatial layers may have a longer feedback reporting period compared to the non-dominant spatial layers. The base station may send a CSI reporting configuration that includes the reporting periods for the dominant spatial layers and the non-dominant spatial layers. The UE may send CSI reports for the dominant spatial layers and the non-dominant spatial layers according to different periods. For aperiodic reporting, the base station may send downlink control information to trigger a CSI report for the dominant spatial layer. If dominant layer reporting is not enabled, the UE may report CSI for the non-dominant layer. If full layer reporting is enabled, the UE may send CSI reports for both the dominant spatial layers and the non-dominant spatial layers.

[0006] A method for wireless communication at a UE is described. The method may include: receiving, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; sending, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer; and sending, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer.

[0007] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a 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: receive, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; send, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer; and send, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer.

[0008] Describes another apparatus for wireless communication at a UE. The apparatus may include: a unit for receiving channel state information configuration from a base station, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; a unit for transmitting a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and a unit for transmitting a second channel state information report for the non-dominant spatial layer according to the second feedback reporting period.

[0009] Describes a non-transitory computer-readable medium storing code for wireless communication at a UE. The code may include instructions executable by a processor to perform the following operations: receive channel state information configuration from a base station, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; transmit a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and transmit a second channel state information report for the non-dominant spatial layer according to the second feedback reporting period.

[0010] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for performing the following operations: receive downlink control information based on transmitting the first channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report.

[0011] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, receiving the channel state information configuration may include operations, features, units, or instructions for performing the following operations: receive channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer.

[0012] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first codebook may be different from the second codebook.

[0013] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for performing the following operations: transmit a precoding matrix indicator report including a layer indicator corresponding to the dominant spatial layer to the base station.

[0014] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: sending a precoding matrix indicator report indicating that one or more spatial layers may be dominant spatial layers to a base station, where the one or more spatial layers may be indicated based on a rank indicator of the precoding matrix indicator report.

[0015] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the number of one or more spatial layers may be based on the value of a rank indicator.

[0016] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first channel state information report includes channel state information only for a dominant spatial layer or a full-layer report for each spatial layer based on a channel state information configuration.

[0017] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first channel state information report includes channel quality information for non-dominant spatial layers and dominant spatial layers.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: determining an updated precoder for a dominant spatial layer; and sending uplink control information indicating the updated precoder for the dominant spatial layer to a base station, where an indicator in the uplink control information indicates that the updated precoder may be included in the uplink control information.

[0019] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first feedback reporting period for non-dominant spatial layers may be less than a second feedback reporting period for dominant spatial layers.

[0020] A method for wireless communication at a base station is described. The method may include: sending a channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for non-dominant spatial layers, where the first feedback reporting period is different from the second feedback reporting period; receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and receiving a second channel state information report for at least the non-dominant spatial layers according to the second feedback reporting period.

[0021] Describes an apparatus for wireless communication at a base station. The apparatus may include a processor, a 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 perform the following operations: send a channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; receive a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and receive a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0022] Describes another apparatus for wireless communication at a base station. The apparatus may include: a unit for sending a channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; a unit for receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and a unit for receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0023] Describes a non-transitory computer-readable medium storing code for wireless communication at a base station. The code may include instructions executable by a processor to perform the following operations: send a channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; receive a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and receive a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0024] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for performing the following operations: send downlink control information based on receiving the first channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report.

[0025] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for performing the following operations: send a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer.

[0026] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first codebook may be different from the second codebook.

[0027] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for: receiving, from a UE, a precoding matrix indicator report including a layer indicator corresponding to a dominant spatial layer.

[0028] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for: receiving, from a UE, a precoding matrix indicator report indicating that one or more spatial layers may be dominant spatial layers, where the one or more spatial layers may be indicated based on a rank indicator of the precoding matrix indicator report.

[0029] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the number of one or more spatial layers may be based on the value of a rank indicator.

[0030] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first channel state information report includes channel quality information for non-dominant spatial layers and dominant spatial layers.

[0031] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for: receiving, from a UE, uplink control information, where the uplink control information indicates an updated precoder for a dominant spatial layer, and an indicator in the uplink control information indicates that the updated precoder may be included in the uplink control information.

[0032] A method for wireless communication at a UE is described. The method may include: receiving, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for non-dominant spatial layers, where the first codebook is different from the second codebook; transmitting, based on the second codebook, a first channel state information report for non-dominant spatial layers; receiving first downlink control information that configures the UE to report channel state information for dominant spatial layers and non-dominant spatial layers; and transmitting, based on the first codebook and the second codebook, a second channel state information report for non-dominant spatial layers and dominant spatial layers.

[0033] A device for wireless communication at a UE is described. The device may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the device to perform the following operations: receive, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; transmit, based on the second codebook, a first channel state information report for the non-dominant spatial layer; receive first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and transmit, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0034] Another device for wireless communication at a UE is described. The device may include: a unit for receiving, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; transmitting, based on the second codebook, a first channel state information report for the non-dominant spatial layer; a unit for receiving first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and a unit for transmitting, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0035] 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 perform the following operations: receive, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; transmit, based on the second codebook, a first channel state information report for the non-dominant spatial layer; receive first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and transmit, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0036] Some examples of the methods, devices, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following operation: receive second downlink control information from a base station that configures the UE to disable reporting channel state information for the dominant spatial layer.

[0037] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving downlink control information based on sending a second channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report and the second channel state information report.

[0038] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: sending a precoding matrix indicator report to a base station, the precoding matrix indicator report including a layer indicator corresponding to a dominant spatial layer.

[0039] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: sending a precoding matrix indicator report to a base station indicating that one or more layers may be a dominant spatial layer, wherein the one or more layers may be indicated based on a rank indicator of the precoding matrix indicator report.

[0040] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first channel state information report includes channel quality information for non-dominant spatial layers and dominant spatial layers.

[0041] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining an updated precoder for a dominant spatial layer; and sending uplink control information to a base station to indicate the updated precoder for the dominant spatial layer, wherein an indicator in the uplink control information indicates that the updated precoder may be included in the uplink control information.

[0042] A method for wireless communication at a base station is described. The method may include: sending channel state information configuration to a UE indicating a first codebook for a dominant spatial layer and a second codebook for non-dominant spatial layers, wherein the first codebook is different from the second codebook; receiving a first channel state information report for non-dominant spatial layers based on the second codebook; sending first downlink control information that configures the UE to report channel state information for dominant spatial layers and non-dominant spatial layers; and receiving a second channel state information report for non-dominant spatial layers and dominant spatial layers based on the first codebook and the second codebook.

[0043] Describes an apparatus for wireless communication at a base station. The apparatus may include a processor, a 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 perform the following operations: send to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; receive a first channel state information report for the non-dominant spatial layer based on the second codebook; send first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and receive a second channel state information report for the non-dominant spatial layer and the dominant spatial layer based on the first codebook and the second codebook.

[0044] Describes another apparatus for wireless communication at a base station. The apparatus may include: a unit for sending to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; a unit for receiving a first channel state information report for the non-dominant spatial layer based on the second codebook; a unit for sending first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and a unit for receiving a second channel state information report for the non-dominant spatial layer and the dominant spatial layer based on the first codebook and the second codebook.

[0045] Describes a non-transitory computer-readable medium storing code for wireless communication at a base station. The code may include instructions executable by a processor to perform the following operations: send to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; receive a first channel state information report for the non-dominant spatial layer based on the second codebook; send first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and receive a second channel state information report for the non-dominant spatial layer and the dominant spatial layer based on the first codebook and the second codebook.

[0046] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, units, or instructions for performing the following operation: send to the UE second downlink control information that configures the UE to disable reporting of channel state information for the dominant spatial layer.

[0047] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: transmitting downlink control information based on receiving a second channel state information report, the downlink control information including an acknowledgment feedback for the first channel state information report and the second channel state information report. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 FIG. shows an example of a wireless communication system supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0049] Figure 2 FIG. shows an example of a wireless communication system supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0050] Figure 3 FIG. shows an example of a periodic CSI reporting procedure flow supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0051] Figure 4 FIG. shows an example of an aperiodic CSI reporting procedure flow supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0052] Figure 5 and 6 FIG. shows a block diagram of a device supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0053] Figure 7 FIG. shows a block diagram of a communication manager supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0054] Figure 8 FIG. shows a diagram of a system including a device supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0055] Figure 9 and 10 FIG. shows a block diagram of a device supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0056] Figure 11 FIG. shows a block diagram of a communication manager supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0057] Figure 12 FIG. shows a diagram of a system including a device supporting layer-specific feedback periods in accordance with aspects of the present disclosure.

[0058] Figures 13 to 18 FIG. shows a flowchart illustrating a method supporting layer-specific feedback periods in accordance with aspects of the present disclosure. Detailed Implementation Manner

[0059] A base station and a user equipment (UE) can communicate using beamformed communication. A transmitting device can apply precoding to data and transmit the data directionally via one or more spatial layers or data streams according to the precoding. In some cases, each spatial layer can have a different direction, and some spatial layers can point more directly to the receiving device than other spatial layers. Some spatial layers can be strong spatial layers, and the strong spatial layers can transmit beamformed information in the direction close to the UE. Some other spatial layers can be weak spatial layers, and the weak spatial layers may not be precisely pointed to the UE. The UE can receive the beamformed transmission from the base station and provide feedback in response. For example, the base station can transmit a channel state information (CSI) reference signal (CSI-RS). The UE can measure the CSI-RS and send a report for the measurement to the base station. In some systems, feedback such as a CSI report can include each CSI component. For example, the feedback can include a precoding matrix indicator (PMI), a rank indicator (RI), and a channel quality indicator (CQI), all of which can be sent on the same uplink shared channel or uplink control channel. The feedback can indicate the beam quality and whether any beam should be updated to provide a stronger signal.

[0060] In some cases, the UE may perform beam updates frequently. For example, a high Doppler scenario may result in more frequent beam updates to capture channel variations. More frequent CSI triggers can use significant overhead to send CSI reports. For example, frequent CSI reports may use more resources for CSI-RS pilot signals, use downlink control channel resources to send downlink control information for triggering CSI reports, use uplink resources (e.g., uplink shared channel resources or uplink control channel resources) to carry CSI reports, or any combination thereof.

[0061] The wireless communication systems described herein support techniques for efficient CSI reporting. For example, the UE can be configured with different periodicities or triggers to report CSI for dominant (e.g., strong) spatial layers and non-dominant (e.g., weak) spatial layers. The UE can have one or more dominant spatial layers and one or more non-dominant spatial layers. In some cases, the UE can send an indication to the base station about which spatial layers correspond to the dominant spatial layers. In some cases, the dominant spatial layers and non-dominant spatial layers can be configured with different codebooks or codebook types. These techniques can reduce the reporting frequency for dominant spatial layers, which can improve resource utilization and reduce the overhead for CSI reporting.

[0062] For periodic reporting, the dominant spatial layer may have a different CSI reporting period compared to the non-dominant spatial layers. For example, the dominant spatial layer may have a longer feedback reporting period compared to the non-dominant spatial layers. The base station may send a CSI reporting configuration that includes the reporting periods for the dominant and non-dominant spatial layers. The UE may send CSI reports for the dominant and non-dominant spatial layers according to different periods. For aperiodic reporting, the base station may send downlink control information to trigger a CSI report for the dominant spatial layer. If dominant layer reporting is not enabled, the UE may report CSI for the non-dominant layer. If full layer reporting is enabled, the UE may send CSI reports for both the dominant and non-dominant spatial layers.

[0063] Aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated by, and described with reference to, apparatus diagrams, system diagrams, and flowcharts that relate to layer-specific feedback periods.

[0064] Figure 1 An example of a wireless communication system 100 that supports layer-specific feedback periods in accordance with aspects of the present disclosure is shown. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an enhanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices, or any combination thereof.

[0065] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100 and may be devices of different forms or having different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110, and the UEs 115 and the base stations 105 may establish one or more communication links 125 over the coverage area 110. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 may support the transmission of signals according to one or more radio access technologies.

[0066] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices of different forms or having different capabilities. In Figure 1Some example UEs 115 are shown herein. The UEs 115 described herein can communicate with various types of devices, such as other UEs 115, base stations 105, or network devices (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices), as Figure 1 shown herein.

[0067] Base station 105 can communicate with core network 130, or with each other, or both. For example, base station 105 can interface with core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base station 105 can communicate directly (e.g., directly between base stations 105) with each other via backhaul link 120 (e.g., via X2, Xn, or other interfaces), or can communicate with each other indirectly (e.g., via core network 130), or both. In some examples, backhaul link 120 can be or include one or more wireless links.

[0068] One or more of the base stations 105 described herein can include or can be referred to by those skilled in the art as a base station transceiver, radio base station, access point, radio transceiver, Node B, evolved Node B (eNB), next generation Node B, or Gigabit Node B (any of which can be referred to as a gNB), home Node B, home evolved Node B, or some other suitable term.

[0069] UE 115 can include or can be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or some other suitable term, where "device" can also be referred to as a unit, station, terminal, or client, etc. UE 115 can also include or can be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 can include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine type communication (MTC) device, etc., which can be implemented in various articles such as appliances, or vehicles, meters, etc.

[0070] The UEs 115 described herein can communicate with various types of devices, such as other UEs 115 that can sometimes act as repeaters, as well as base stations 105 and network devices, including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc., as Figure 1 shown herein.

[0071] UE 115 and base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating the operation of the carrier, user data, or other signaling. The wireless communication system 100 may support communication with UE 115 using carrier aggregation or multi-carrier operation. According to a carrier aggregation configuration, UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers.

[0072] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling for coordinating the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunications system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be placed according to a channel raster for discovery by UE 115. A carrier may operate in stand-alone mode, where UE 115 performs initial acquisition and connection via the carrier, or the carrier may operate in non-stand-alone mode, where a different carrier (e.g., of the same or a different radio access technology) is used to anchor the connection.

[0073] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from UE 115 to base station 105 or a downlink transmission from base station 105 to UE 115. A carrier may carry downlink or uplink communication (e.g., in FDD mode) or may be configured to carry both downlink and uplink communication (e.g., in TDD mode).

[0074] A carrier can be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth can be referred to as the "system bandwidth" of the carrier or the wireless communication system 100. For example, the carrier bandwidth can be one of several defined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communication system 100 (e.g., the base station 105, the UE 115, or both) can have a hardware configuration that supports communication on a specific carrier bandwidth, or can be configurable to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 can include a base station 105 or a UE 115 that supports simultaneous communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 can be configured to operate on a portion (e.g., a subband, a BWP) or all of the carrier bandwidth.

[0075] The signal waveform transmitted on a carrier can be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing an MCM technique, a resource element can include a symbol period (e.g., the duration of a modulated symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate can be for the UE 115. Wireless communication resources can refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further increase the data rate or data integrity for communication with the UE 115.

[0076] One or more numerologies can be supported for a carrier, where a numerology can include a subcarrier spacing (Δf) and a cyclic prefix. A carrier can be divided into one or more BWPs having the same or different numerologies. In some examples, the UE 115 can be configured with multiple BWPs. In some examples, a single BWP for a carrier can be active at a given time, and communication for the UE 115 can be restricted to one or more active BWPs.

[0077] It can be in a basic time unit, which can, for example, refer to T s = 1 / (Δf max ·N f ) seconds of sampling period, where, Δf maxmay represent the maximum supported subcarrier spacing, and N f may represent a multiple of the maximum supported discrete Fourier transform (DFT) size) to represent a time interval for base station 105 or UE 115. The time intervals of communication resources may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0078] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix added in front of each symbol period). In some wireless communication systems 100, a time slot may be further divided into a plurality of mini-slots each containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f number of) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0079] A subframe, time slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of wireless communication system 100 may be dynamically selected (e.g., in the form of a burst of shortened TTIs (sTTIs)).

[0080] Physical channels can be multiplexed on a carrier according to various techniques. For example, one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels on a downlink carrier. A control region for a physical control channel (e.g., a control resource set (CORESET)) can be defined by the number of symbol periods and can extend across the system bandwidth of the carrier or a subset of the system bandwidth. One or more control regions (e.g., CORESETs) can be configured for a group of UEs 115. For example, one or more of the UEs 115 can monitor or search a control region for control information according to one or more search space sets, and each search space set can include one or more control channel candidates at one or more aggregation levels arranged in a cascaded manner. The aggregation level for a control channel candidate can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with the coded information for a control information format having a given payload size. The search space set can include a common search space set configured to send control information to multiple UEs 115 and a UE-specific search space set for sending control information to a specific UE 115.

[0081] Each base station 105 can provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" can refer to a logical communication entity for communicating with a base station 105 (e.g., via a carrier) and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other identifier) for distinguishing adjacent cells. In some examples, a cell can also refer to a geographic coverage area 110 or a portion of the geographic coverage area 110 (e.g., a sector) on which the logical communication entity operates. Depending on various factors (such as the capabilities of the base station 105), the scope of such a cell can range from a smaller area (e.g., a building, a subset of a building) to a larger area. For example, a cell can be or include a building, a subset of a building, or an external space between or overlapping with the geographic coverage areas 110, etc.

[0082] Macro cells typically cover a relatively large geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access by UEs 115 having a service subscription with the network provider that supports the macro cell. In contrast to macro cells, small cells can be associated with a lower-power base station 105, and small cells can operate in the same or different (e.g., licensed, unlicensed) frequency bands compared to macro cells. A small cell can provide unrestricted access to UEs 115 having a service subscription with the network provider, or can provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a residence or office). The base station 105 can support one or more cells and can also support communication on one or more cells using one or more component carriers.

[0083] In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that can provide access for different types of devices.

[0084] In some examples, the base station 105 can be movable and thus provide communication coverage for a mobile geographical coverage area 110. In some examples, different geographical coverage areas 110 associated with different technologies can overlap, but different geographical coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographical coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network where different types of base stations 105 use the same or different radio access technologies to provide coverage for respective geographical coverage areas 110.

[0085] The wireless communication system 100 can support synchronous or asynchronous operation. For synchronous operation, the base stations 105 can have similar frame timings, and transmissions from different base stations 105 can be approximately aligned in time. For asynchronous operation, the base stations 105 can have different frame timings, and in some examples, transmissions from different base stations 105 can not be aligned in time. The techniques described herein can be used for synchronous or asynchronous operation.

[0086] Some UEs 115 (e.g., MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with the base station 105 without human intervention. In some examples, M2M communication or MTC can include communication from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application, where the application utilizes the information or presents the information to a human who interacts with the application. Some UEs 115 can be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, device monitoring, healthcare monitoring, wildlife monitoring, climate and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business billing.

[0087] Some UEs 115 can be configured to operate in power-saving modes, e.g., half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception rather than simultaneous transmission and reception). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UEs 115 include entering a power-saving deep sleep mode when not participating in active communication, operating on limited bandwidths (e.g., according to narrowband communication), or a combination of these techniques. For example, some UEs 115 can be configured for operation using a narrowband protocol type that is associated with a defined portion or range within a carrier, within a guard band of the carrier, or external to the carrier (e.g., a set of subcarriers or resource blocks (RBs)).

[0088] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. The UE 115 can be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can be supported by one or more mission-critical services such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably herein.

[0089] In some examples, UE 115 is capable of communicating directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of base station 105 or otherwise unable to receive transmissions from base station 105. In some examples, groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base station 105.

[0090] In some systems, D2D communication link 135 may be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these. Vehicles may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information related to the V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure (such as a roadside unit), or communicate with the network via one or more network nodes (e.g., base station 105) using vehicle-to-network (V2N) communication, or perform both operations.

[0091] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets to or interconnects with an external network (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for a UE 115 served by a base station 105 associated with the core network 130. User IP packets may be transmitted through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to IP services 150 for one or more network operators. The IP services 150 may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet switched streaming services.

[0092] Some network devices in the network device (such as the base station 105) may include subcomponents such as the access network entity 140, and the access network entity 140 may be an example of an access node controller (ANC). Each access network entity 140 may communicate with the UE 115 through one or more other access network transmission entities 145 (which may be referred to as radio heads, intelligent radio heads, or transmit / receive points (TRPs)). Each access network transmission entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or the base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or combined into a single network device (e.g., the base station 105).

[0093] The wireless communication system 100 may operate using one or more frequency bands (generally in the range of 300 megahertz (MHz) to 300 gigahertz (GHz)). Generally, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or the decimeter band because the wavelength range is approximately from one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, but these waves can penetrate buildings sufficiently to enable a macro cell to serve a UE 115 located indoors. Compared with the transmission of smaller frequencies and longer waves using the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, the transmission of UHF waves may be associated with smaller antennas and shorter distances (e.g., less than 100 kilometers).

[0094] The wireless communication system 100 may also operate in the super high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also referred to as the centimeter band) or in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also referred to as the millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may be even smaller and more closely spaced compared to UHF antennas. In some examples, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may suffer even greater atmospheric attenuation and shorter distances compared to SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the specified use of frequency bands across these frequency regions may vary according to the country or regulatory body.

[0095] The wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed frequency band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed radio frequency spectrum band, devices such as the base station 105 and the UE 115 may employ carrier sensing for collision detection and avoidance. In some examples, the operation in the unlicensed frequency band may be based on a carrier aggregation configuration (e.g., LAA) that combines a component carrier operating in a licensed frequency band. The operation in the unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer (P2P) transmissions, or device-to-device (D2D) transmissions, etc.

[0096] The base station 105 or the 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) communication, or beamforming. The antennas of the base station 105 or the UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array having a number of rows and columns of antenna ports that the base station 105 may use to support beamforming for communication with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0097] Base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such a technique can be referred to as spatial multiplexing. For example, a transmitting device can transmit multiple signals via different antennas or different combinations of antennas. Similarly, a receiving device can receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream and can carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports 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 multi-user MIMO (MU-MIMO) (where multiple spatial layers are transmitted to multiple devices).

[0098] Beamforming (which can also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., base station 105, UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via the antenna elements of an antenna array such that some signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals transmitted via the antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to the signals carried via the antenna elements associated with the device. The adjustment associated with each of the antenna elements can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0099] As part of the beamforming operation, base station 105 or UE 115 can use beam scanning techniques. For example, base station 105 can use multiple antennas or an antenna array (e.g., an antenna panel) to perform beamforming operations for directional communication with UE 115. Base station 105 can transmit some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) multiple times in different directions. For example, base station 105 can transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions can be used (e.g., by the transmitting device such as base station 105 or by the receiving device such as UE 115) to identify the beam direction for subsequent transmissions or receptions performed by base station 105.

[0100] Base station 105 may transmit some signals, such as data signals associated with a particular receiving device (e.g., UE 115), in a single beam direction (e.g., the direction associated with a particular receiving device). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more of the signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 that has the highest signal quality or otherwise acceptable signal quality.

[0101] In some examples, transmissions performed by a device (e.g., by base station 105 or UE 115) may be carried out using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from base station 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. Base station 105 may transmit reference signals that may or may not be precoded (e.g., cell-specific reference signal (CRS), CSI-RS). UE 115 may provide feedback for beam selection, and the feedback may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., for identifying beam directions for subsequent transmissions or receptions by UE 115) or to transmit signals in a single direction (e.g., for transmitting data to a receiving device).

[0102] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, a receiving device (e.g., UE 115) may attempt multiple receive configurations (e.g., directional listening). For example, the receiving device may receive by receiving via different antenna sub-arrays, by processing received signals according to different antenna sub-arrays, by receiving according to different sets of receive beamforming weights (e.g., different sets of directional listening weights) applied to signals received at multiple antenna elements of the antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array (any of the above operations may be referred to as "listening" according to different receive configurations or receive directions), thereby attempting multiple receive directions. In some examples, the receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions).

[0103] Wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or packet data convergence protocol (PDCP) layer may be IP-based. The radio link control (RLC) layer may perform packet segmentation and reassembly for transmission over logical channels. The media access control (MAC) layer may perform priority handling and multiplexing of logical channels to transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support 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 (which supports radio bearers for user plane data) between UE 115 and base station 105 or core network 130. At the physical layer, transport channels may be mapped to physical channels.

[0104] UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. Hybrid Automatic Repeat reQuest (HARQ) feedback is a technique for increasing the likelihood that data is correctly received over communication link 125. HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), Forward Error Correction (FEC), and retransmission (e.g., Automatic Repeat reQuest (ARQ)). HARQ can improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device may support HARQ feedback in the same time slot, where the device may provide HARQ feedback for data received in previous symbols in the particular time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0105] Wireless communication system 100 may support techniques for efficient CSI reporting. For example, UE 115 may be configured with different periodicities or triggers to report CSI for a dominant spatial layer and non-dominant (e.g., weaker) spatial layers. UE 115 may have one or more dominant spatial layers and one or more non-dominant spatial layers. In some cases, UE 115 may send an indication to base station 105 as to which spatial layers correspond to the dominant spatial layer. In some cases, the dominant spatial layer and non-dominant spatial layers may be configured with different codebooks or codebook types. These techniques can reduce the reporting frequency for the dominant spatial layer, which can improve resource utilization and reduce the overhead for CSI reporting.

[0106] For periodic reporting, the dominant spatial layer may have a different CSI reporting period compared to the non-dominant spatial layer. For example, the dominant spatial layer may have a longer feedback reporting period compared to the non-dominant spatial layer. Base station 105 may send a CSI reporting configuration to UE115 that includes the reporting periods for the dominant spatial layer and the non-dominant spatial layer. UE 115 may send CSI reports for the non-dominant spatial layer according to the period for the non-dominant spatial layer, and UE 115 may send CSI reports for the dominant spatial layer according to the period for the non-dominant spatial layer. In some cases, UE 115 may generally use fewer uplink resources to transmit CSI because UE 115 may send CSI for the dominant spatial layer less frequently.

[0107] For non-periodic reporting, the base station 105 may send downlink control information to trigger reporting for the dominant spatial layer. For example, if dominant layer reporting is not enabled, the UE 115 may report CSI for non-dominant layers. The base station 105 may send CSI report configuration to the UE 115 to configure CSI reporting for the dominant and non-dominant layers. If full layer reporting is enabled, the UE 115 may send CSI reports for both the dominant and non-dominant spatial layers. Otherwise, the UE 115 may send CSI reports only for the non-dominant spatial layer.

[0108] Figure 2 FIG. 200 illustrates an example of a wireless communication system 200 supporting layer-specific feedback cycles in accordance with aspects of the present disclosure. The wireless communication system 200 includes a UE 115-a and a base station 105-a, which may be respective examples of the UE 115 and the base station 105 described with reference to Figure 1 wireless communication system 100.

[0109] The base station 105-a and the UE 115-a may communicate using beamformed communication. The transmitting device may apply precoding to data and transmit the data directionally via one or more layers according to the precoding. In some cases, each spatial layer may have a different direction, where some spatial layers may point more directly to the receiving device than other spatial layers.

[0110] For example, the base station 105-a may transmit to the UE 115-a using multiple spatial layers. Some spatial layers may be strong spatial layers (such as strong layer 205), and the strong spatial layers may transmit beamformed information in a direction close to the UE 115-a. Some other spatial layers (such as weak layer 210-a) may also carry information, but the weak spatial layer 210 may not be pointed precisely at the UE 115-a. The base station 105-a may have one or more strong spatial layers or one or more weak spatial layers or one or more of each of the strong and weak spatial layers. In some cases, the dominant spatial layer may be stronger than the weak spatial layer, but the weak spatial layer may generally provide sufficient signal quality or strength.

[0111] The UE 115-a may receive transmissions from the base station 105-a and provide feedback in response. For example, the base station 105-a may send CSI-RS. The UE 115-a may measure the CSI-RS and send a report for the measurement to the base station 105-a. In some systems, feedback such as CSI reports may include each CSI component. For example, the feedback may include PMI, RI, and CQI, all of which may be sent on the same uplink shared channel or uplink control channel. The feedback may indicate beam quality and whether any beams should be updated to provide a stronger signal.

[0112] In some cases, UE 115-a may perform beam updates frequently. For example, a high Doppler scenario may result in more frequent beam updates to capture channel changes. More frequent CSI triggers can use significant overhead to send CSI reports. For example, frequent CSI reports can allocate more resources for CSI-RS pilot signals, use downlink control channel resources to send downlink control information for triggering CSI reports, use uplink resources (e.g., uplink shared channel resources or uplink control channel resources) to carry CSI reports, or any combination thereof.

[0113] In some current systems, UE 115 may report CSI for both strong and weak spatial layers each time a CSI report is triggered. However, even in cases of frequent CSI report triggers, the update frequency of the strong spatial layer may be lower than that of the weak spatial layer. For example, UE 115-a may perform an update 215 to change from weak layer 210-a to weak layer 210-b, but UE 115-a may not perform an update for the strong layer 205. Thus, in these systems, these wireless communication systems may allocate resources to report CSI for spatial layers that may not be updated, which may be an inefficient use of wireless resources.

[0114] Wireless communication system 200 supports techniques for efficient CSI reporting. For example, UE 115-a may be configured with different periods or triggers to report CSI for dominant (e.g., strong) and non-dominant (e.g., weak) spatial layers. UE 115-a may have one or more dominant spatial layers (e.g., including strong layer 205) and one or more non-dominant spatial layers (e.g., including weak layer 210-b). In some cases, UE 115-a may send an indication to base station 105-a regarding which spatial layers correspond to the dominant spatial layers. In some cases, the dominant and non-dominant spatial layers may be configured with different codebooks or codebook types. These techniques can reduce the reporting frequency for the dominant spatial layer, which can improve resource utilization and reduce the overhead for CSI reporting.

[0115] For periodic reporting, the dominant spatial layer may have a different CSI reporting period compared to the non-dominant spatial layer. For example, the dominant spatial layer may have a longer feedback reporting period compared to the non-dominant spatial layer. The base station 105-a may send a CSI reporting configuration to the UE 115-a that includes the reporting periods for the dominant and non-dominant spatial layers. The UE 115-a may send a CSI report for the non-dominant spatial layer according to the period for the non-dominant spatial layer, and the UE 115-a may send a CSI report for the dominant spatial layer according to the period for the dominant spatial layer. In some cases, the UE 115-a may generally use fewer uplink resources to transmit CSI because the UE 115-a may send CSI for the dominant spatial layer less frequently. Refer to Figure 3 Examples of periodic reporting with different periods for the dominant and non-dominant spatial layers are described in more detail.

[0116] For aperiodic reporting, the base station 105-a may send downlink control information to trigger a report for the dominant spatial layer. For example, if dominant layer reporting is not enabled, the UE 115-a may report CSI for the non-dominant layer. The base station 105-a may send a CSI reporting configuration to the UE 115-a to configure CSI reporting for the dominant and non-dominant layers. If full layer reporting is enabled, the UE 115-a may send CSI reports for both the dominant and non-dominant spatial layers. Otherwise, the UE 115-a may only send a CSI report for the non-dominant spatial layer. Refer to Figure 4 Examples of these techniques for aperiodic reporting are described in more detail.

[0117] In some examples, the base station 105-a may configure codebooks for the dominant and non-dominant spatial layers separately. For example, the base station 105-a may configure a hybrid codebook type for the dominant and non-dominant spatial layers. The dominant spatial layer or the non-dominant spatial layer, or both, may be configured with a semi-open loop precoder, a closed loop precoder, a type 1 precoder, a type 2 precoder, or an enhanced type 2 precoder. In some cases, the dominant and non-dominant spatial layers may have different ranks. For example, the first spatial layer may be configured as the dominant spatial layer with a type 1 PMI, and the second spatial layer may be configured as the non-dominant spatial layer with a semi-open loop PMI. In another example, the dominant layer may be configured as a type 2 PMI, and the non-dominant layer may be configured as a type 1 or semi-open loop PMI. Other examples or combinations may be configured for the dominant and non-dominant layers.

[0118] In some cases, UE 115-a may send an indication of one or more dominant spatial layers to base station 105-a. For example, UE 115-a may use the layer indication (LI) field in the PMI report to indicate the dominant spatial layer. In some cases, when full layer PMI reporting is enabled, UE 115-a may indicate the dominant spatial layer via the LI field. In some cases, if UE 115-a indicates the dominant spatial layer via the LI field, UE 115-a may support a single dominant layer. In some other examples, the dominant layer may be the first m layers in the feedback PMI. The value of m may be less than the rank indicated by the PMI report. In some cases, the value of m may be pre-configured at UE 115-a, or predefined or configured via RRC signaling. For example, UE 115-a may send a PMI report indicating the value of m and the rank, such as (1,2), (1,3), and (2,4). By using the first m spatial layers in the PMI report, UE 115-a may support multiple dominant spatial layers.

[0119] In some examples, base station 105-a and UE 115-a may synchronize on PMI information. For example, when CSI is reported periodically, if the full layer report is not correctly received at base station 105-a, subsequent partial layer reports may be ambiguous. For example, UE 115-a may assume that base station 105-a did not receive the information of the dominant layer in the CSI report. Therefore, to synchronize the PMI information, base station 105-a may send an acknowledgement feedback for the full layer report in the downlink control information. For example, base station 105-a may include an acknowledgement report for the full layer report sent in the uplink control information in the downlink control information.

[0120] In some examples, UE 115-a may report an update for the dominant spatial layer. For example, if the precoder for the dominant spatial layer has changed, UE 115-a may report the dominant spatial layer. In some cases, UE 115-a may include additional signaling in the uplink control information to indicate whether the CSI report includes an updated dominant layer. In some cases, UE 115-a may indicate the updated precoder for the dominant spatial layer.

[0121] In some examples, a partial layer report may include a CQI for all spatial layers. For example, UE 115-a may send a CSI report for a non-dominant spatial layer and include the CQI for the dominant and non-dominant spatial layers. The CQI may be updated when determining the PMI at an all-layer CSI report. In some cases, UE 115-a may use singular value decomposition to calculate an all-layer PMI or CQI to obtain the first domain singular vector of the precoder as the dominant layer. In some cases, the PMI for a partial layer may be calculated by earlier reporting the null space of the precoder of the dominant layer.

[0122] Figure 3 FIG. 300 illustrates an example of a periodic reporting procedure flow that supports a layer-specific feedback period according to aspects of the present disclosure. The periodic reporting procedure flow may be implemented by UE 115-b or base station 105-b or both. UE 115-b and base station 105-b may be examples of UE 115 and base station 105 as referenced Figure 1 and 2 described.

[0123] UE 115-b may be configured with multiple spatial layers for communicating with base station 105-b. In some cases, UE 115-b may be configured with one or more dominant spatial layers and one or more non-dominant spatial layers. In some cases, UE 115-b may send an indication of the dominant spatial layer to base station 105-b. For example, UE 115-b may determine the dominant spatial layer based on the signal strength of the spatial layer or the rate at which the spatial layer is updated. In some cases, the dominant spatial layer may be referred to as a strong spatial layer, where the signal strength measurement for the dominant spatial layer may be greater than the signal strength measurement for the non-dominant spatial layer. UE 115-b may indicate the dominant spatial layer to base station 105-b via a PMI report. For example, the dominant spatial layer may be indicated by the layer indication in the PMI report, or UE 115-b may indicate one or more dominant spatial layers corresponding to the first m spatial layers in the PMI report.

[0124] At 305, base station 105-b may send a CSI configuration to UE 115-b, the CSI configuration indicating a first feedback reporting period 310 for the dominant spatial layer and a second feedback reporting period 315 for the non-dominant spatial layer. In some cases, the first feedback reporting period may be different from the second feedback reporting period. In some cases, the CSI configuration may be sent via RRC signaling.

[0125] The first feedback reporting period 310 can be longer than the second feedback reporting period 315. For example, the first feedback reporting period 310 can be 20 milliseconds, and the second feedback reporting period 315 can be 10 milliseconds. In some other examples, the periods can be different. For example, the first feedback reporting period 310 is 5 milliseconds, and the second feedback reporting period 315 is 20 milliseconds.

[0126] In some cases, the CSI configuration can indicate codebooks for the dominant spatial layer and the non-dominant spatial layer. In some cases, the codebooks for the dominant spatial layer and the non-dominant spatial layer can be different. For example, the dominant spatial layer can use a type 2 codebook, and the non-dominant spatial layer can use a type 1 codebook.

[0127] At 320, UE 115-b can send a first CSI report for at least the dominant spatial layer according to the first feedback reporting period. For example, at 320, UE 115-b can send a first CSI report including CSI for the dominant spatial layer w1 and the non-dominant spatial layer w2. The first CSI report can be encoded according to the first codebook or the second codebook or both.

[0128] In some cases, UE 115-b can receive downlink control information based on sending the first CSI report. The downlink control information includes an acknowledgement feedback for the first CSI report. The PMI can be synchronized between UE 115-b and the base station 105-b in response to the acknowledgement feedback of the full layer report.

[0129] At 325, UE 115-b can send a second CSI report for the non-dominant spatial layer according to the second feedback reporting period. For example, the second CSI report can include CSI elements only for the non-dominant spatial layer. By reporting CSI only for the non-dominant spatial layer, UE 115-b can use fewer resources to send CSI, thus reducing the overhead for CSI reporting. In some examples, the second CSI report can include the CQI for the dominant spatial layer and the non-dominant spatial layer.

[0130] At 330, UE 115-b can send a third CSI report for the dominant spatial layer according to the first feedback reporting period. The third CSI report can also include CSI for the non-dominant spatial layer. For example, the first feedback reporting period 310 and the second feedback reporting period 315 can coincide at 330, such that CSI reports are triggered for both the dominant spatial layer and the non-dominant spatial layer.

[0131] Figure 4An example of an aperiodic CSI reporting procedure flow 400 that supports layer-specific feedback periodicity in accordance with aspects of the present disclosure is shown. The aperiodic reporting procedure flow may be implemented by UE 115-c or base station 105-c or both. UE 115-c and base station 105-c may be examples of UE 115 and base station 105 as referenced Figure 1 and 2 described.

[0132] UE 115-c may be configured with multiple spatial layers for communicating with base station 105-c. In some cases, UE 115-c may be configured with one or more dominant spatial layers and one or more non-dominant spatial layers. In some cases, UE 115-c may send an indication of the dominant spatial layer to base station 105-b via PMI reporting. For example, the dominant spatial layer may be indicated by the layer indication in the PMI report, or UE 115-b may indicate one or more dominant spatial layers corresponding to the first m spatial layers in the PMI report.

[0133] At 405, base station 105-c may send a CSI configuration to UE 115-c, the CSI configuration indicating a first feedback codebook for the dominant spatial layer and a second codebook for the non-dominant spatial layer. In some cases, the codebooks for the dominant spatial layer and the non-dominant spatial layer may be different. For example, the dominant spatial layer may use a type 2 codebook, and the non-dominant spatial layer may use a type 1 codebook. In some cases, the CSI configuration may be sent via RRC signaling. In some examples, the CSI configuration may indicate the period for the dominant spatial layer and the non-dominant spatial layer. For example, UE 115-c may support both a periodic reporting scheme and an aperiodic reporting scheme. In some examples, UE 115-c may be configured for periodic reporting, aperiodic reporting, or both.

[0134] For some non-periodic reporting schemes, UE 115-c may report CSI for the dominant spatial layer as needed. For example, at 410, UE 115-c may receive downlink control information that configures UE 115-c to report CSI for the dominant spatial layer and non-dominant spatial layers. The downlink control information may trigger UE 115-c to send CSI for the dominant spatial layer. At 415, UE 115-c may send a CSI report for the dominant spatial layer w1 and non-dominant spatial layer w2 based on a first codebook or a second codebook or both. In some cases, UE 115-c may be triggered to send a one-time CSI report for the dominant spatial layer, or CSI reporting for the dominant spatial layer may be enabled and disabled. In some cases, CSI reporting for the dominant spatial layer may be triggered or enabled and disabled via a MAC control element. In some cases, UE 115-c may receive second downlink control information that disables CSI reporting for the dominant spatial layer.

[0135] In some cases, UE 115-c may receive downlink control information based on sending a CSI report, the downlink control information including an acknowledgment feedback for CSI reports for the dominant spatial layer and non-dominant spatial layers. The acknowledgment feedback for a full-layer report may synchronize the PMI between UE 115-b and base station 105-b.

[0136] At 420, UE 115-c may send a CSI report for the non-dominant spatial layer based on the second codebook. For example, UE 115-c may not be triggered or configured to report CSI for the dominant spatial layer at 420. Thus, in some cases, the first CSI report may include only CSI for the non-dominant spatial layer w2.

[0137] Figure 5 Block diagram 500 illustrates a device 505 that supports layer-specific feedback cycles in accordance with aspects of the present disclosure. Device 505 may be an example of aspects of UE 115 as described herein. Device 505 may include a receiver 510, a transmitter 515, and a communication manager 520. Device 505 may also include a processor. Each of these components may communicate with one another (e.g., via one or more buses).

[0138] Receiver 510 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback cycles). The information may be passed to other components of device 505. Receiver 510 may utilize a single antenna or an array of multiple antennas.

[0139] Transmitter 515 may provide a unit for transmitting signals generated by other components of device 505. For example, transmitter 515 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback periods). In some examples, transmitter 515 may be co-located with receiver 510 in a transceiver module. Transmitter 515 may utilize a single antenna or an array of multiple antennas.

[0140] Communication manager 520, receiver 510, transmitter 515, or various combinations or various components thereof may be examples of units for performing aspects of a layer-specific feedback period as described herein. For example, communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may support methods for performing one or more of the functions described herein.

[0141] In some examples, communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be implemented in hardware (e.g., with communication management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured to or otherwise supporting a unit for performing the functions described in this disclosure. In some examples, a processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by the processor executing instructions stored in the memory).

[0142] Additionally or alternatively, in some examples, communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be implemented with code executed by a processor (e.g., as communication management software or firmware). If implemented with code executed by a processor, the functions of communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a central processing unit (CPU), an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured to or otherwise supporting a unit for performing the functions described in this disclosure).

[0143] In some examples, the communication manager 520 may be configured to perform various operations (e.g., receive, monitor, transmit) using the receiver 510, the transmitter 515, or both, or otherwise cooperate with the receiver 510, the transmitter 515, or both. For example, the communication manager 520 may receive information from the receiver 510, send information to the transmitter 515, or integrate with the receiver 510, the transmitter 515, or both to receive information, send information, or perform various other operations as described herein.

[0144] According to examples disclosed herein, the communication manager 520 may support wireless communication at the UE. For example, the communication manager 520 may be configured to or otherwise support a unit for receiving from a base station a channel state information configuration indicating a first feedback report period for a dominant spatial layer and a second feedback report period for a non-dominant spatial layer, where the first feedback report period is different from the second feedback report period. The communication manager 520 may be configured to or otherwise support a unit for transmitting a first channel state information report for at least the dominant spatial layer according to the first feedback report period. The communication manager 520 may be configured to or otherwise support a unit for transmitting a second channel state information report for the non-dominant spatial layer according to the second feedback report period.

[0145] Additionally or alternatively, according to examples disclosed herein, the communication manager 520 may support wireless communication at the UE. For example, the communication manager 520 may be configured to or otherwise support a unit for receiving from a base station a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, where the first codebook is different from the second codebook. The communication manager 520 may be configured to or otherwise support a unit for transmitting a first channel state information report for the non-dominant spatial layer based on the second codebook. The communication manager 520 may be configured to or otherwise support a unit for receiving first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer. The communication manager 520 may be configured to or otherwise support a unit for transmitting a second channel state information report for the non-dominant spatial layer and the dominant spatial layer based on the first codebook and the second codebook.

[0146] By including or configuring the communication manager 520 according to the examples described herein, a device 505 (e.g., a processor that controls or is otherwise coupled to the receiver 510, the transmitter 515, the communication manager 520, or a combination thereof) can support techniques for efficient resource utilization and reduced overhead for CSI reporting. For example, by reducing the frequency of reporting CSI for each configured layer, the UE 115 can use fewer resources to report CSI. The UE 115 can update strong or dominant layers less frequently compared to weak or non-dominant layers. The techniques described herein support reporting CSI for dominant layers less frequently while still providing the UE 115 with the opportunity to update weak layers. The reduction in overhead can provide more available resources for the wireless communication system, which can generally increase the throughput in the wireless communication system.

[0147] Figure 6 FIG. 600 is a block diagram illustrating a device 605 that supports layer-specific feedback cycles, in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of the device 505 or the UE 115 described herein. The device 605 may include a receiver 610, a transmitter 615, and a communication manager 620. The device 605 may also include a processor. Each of these components may communicate with one another (e.g., via one or more buses).

[0148] The receiver 610 may provide a unit for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback cycles). The information may be passed to other components of the device 605. The receiver 610 may utilize a single antenna or an array of multiple antennas.

[0149] The transmitter 615 may provide a unit for transmitting signals generated by other components of the device 605. For example, the transmitter 615 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback cycles). In some examples, the transmitter 615 may be co-located with the receiver 610 in a transceiver module. The transmitter 615 may utilize a single antenna or an array of multiple antennas.

[0150] Device 605 or its various components may be examples of units for performing aspects of a layer-specific feedback cycle as described herein. For example, communication manager 620 may include CSI configuration receiving component 625, dominant CSI reporting component 630, non-dominant CSI reporting component 635, dominant CSI reporting trigger component 640, or any combination thereof. Communication manager 620 may be an example of aspects of communication manager 520 as described herein. In some examples, communication manager 620 or its various components may be configured to perform various operations (e.g., receive, monitor, transmit) using receiver 610, transmitter 615, or both, or otherwise in cooperation with receiver 610, transmitter 615, or both. For example, communication manager 620 may receive information from receiver 610, send information to transmitter 615, or integrate in combination with receiver 610, transmitter 615, or both to receive information, send information, or perform various other operations as described herein.

[0151] According to examples as disclosed herein, communication manager 620 may support wireless communication at a UE. CSI configuration receiving component 625 may be configured to or otherwise support a unit for receiving a channel state information configuration from a base station, the channel state information configuration indicating a first feedback reporting cycle for a dominant spatial layer and a second feedback reporting cycle for a non-dominant spatial layer, wherein the first feedback reporting cycle is different from the second feedback reporting cycle. Dominant CSI reporting component 630 may be configured to or otherwise support a unit for sending a first channel state information report for at least the dominant spatial layer according to the first feedback reporting cycle. Non-dominant CSI reporting component 635 may be configured to or otherwise support a unit for sending a second channel state information report for the non-dominant spatial layer according to the second feedback reporting cycle.

[0152] Additionally or alternatively, according to examples as disclosed herein, communication manager 620 may support wireless communication at a UE. For example, CSI configuration receiving component 625 may be configured to or otherwise support a unit for receiving, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, where the first codebook is different from the second codebook. Non-dominant CSI reporting component 635 may be configured to or otherwise support a unit for transmitting, based on the second codebook, a first channel state information report for the non-dominant spatial layer. Dominant CSI reporting trigger component 640 may be configured to or otherwise support a unit for receiving first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer. Dominant CSI reporting component 630 may be configured to or otherwise support a unit for transmitting, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0153] Figure 7 Block diagram 700 illustrates communication manager 720, which supports layer-specific feedback cycles, in accordance with various aspects of the present disclosure. Communication manager 720 may be an example of aspects of communication manager 520, communication manager 620, or both as described herein. Communication manager 720 or its various components may be examples of units for performing various aspects of layer-specific feedback cycles as described herein. For example, communication manager 720 may include CSI configuration receiving component 725, dominant CSI reporting component 730, non-dominant CSI reporting component 735, dominant CSI reporting trigger component 740, CSI feedback component 745, dominant layer indication component 750, dominant layer update component 755, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0154] According to examples as disclosed herein, communication manager 720 may support wireless communication at a UE. CSI configuration receiving component 725 may be configured to or otherwise support a unit for receiving, from a base station, channel state information configuration indicating a first feedback reporting cycle for a dominant spatial layer and a second feedback reporting cycle for a non-dominant spatial layer, where the first feedback reporting cycle is different from the second feedback reporting cycle. Dominant CSI reporting component 730 may be configured to or otherwise support a unit for transmitting, according to the first feedback reporting cycle, a first channel state information report for at least the dominant spatial layer. Non-dominant CSI reporting component 735 may be configured to or otherwise support a unit for transmitting, according to the second feedback reporting cycle, a second channel state information report for the non-dominant spatial layer.

[0155] In some examples, the CSI feedback component 745 can be configured to or otherwise support a unit for receiving downlink control information based on transmitting a first channel state information report, where the downlink control information includes an acknowledgment feedback for the first channel state information report.

[0156] In some examples, to support receiving channel state information configuration, the CSI configuration receiving component 725 can be configured to or otherwise support a unit for receiving a channel state information configuration that indicates a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer. In some examples, the first codebook is different from the second codebook.

[0157] In some examples, the dominant layer indication component 750 can be configured to or otherwise support a unit for transmitting a precoding matrix indicator report including a layer indicator corresponding to the dominant spatial layer to the base station.

[0158] In some examples, the dominant layer indication component 750 can be configured to or otherwise support a unit for transmitting a precoding matrix indicator report indicating that one or more spatial layers are dominant spatial layers to the base station, where the one or more spatial layers are indicated based on a rank indicator of the precoding matrix indicator report. In some examples, the number of the one or more spatial layers is based on the value of the rank indicator.

[0159] In some examples, the first channel state information report includes channel state information only for the dominant spatial layer or a full-layer report for each spatial layer based on the channel state information configuration. In some examples, the second channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

[0160] In some examples, the dominant layer update component 755 can be configured to or otherwise support a unit for determining an updated precoder for the dominant spatial layer. In some examples, the dominant layer update component 755 can be configured to or otherwise support a unit for transmitting uplink control information indicating the updated precoder for the dominant spatial layer to the base station, where an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0161] In some examples, a first feedback reporting period for the non-dominant spatial layer is less than a second feedback reporting period for the dominant spatial layer.

[0162] Additionally or alternatively, according to the examples disclosed herein, the communication manager 720 may support wireless communication at the UE. In some examples, the CSI configuration receiving component 725 may be configured to or otherwise support a unit for receiving, from a base station, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. In some examples, the non-dominant CSI reporting component 735 may be configured to or otherwise support a unit for transmitting, based on the second codebook, a first channel state information report for the non-dominant spatial layer. The dominant CSI reporting trigger component 740 may be configured to or otherwise support a unit for receiving a first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer. In some examples, the dominant CSI reporting component 730 may be configured to or otherwise support a unit for transmitting, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0163] In some examples, the dominant CSI reporting trigger component 740 may be configured to or otherwise support a unit for receiving, from a base station, a second downlink control information that configures the UE to disable reporting channel state information for the dominant spatial layer.

[0164] In some examples, the CSI feedback component 745 may be configured to or otherwise support a unit for receiving, based on transmitting the second channel state information report, downlink control information including acknowledgement feedback for the first channel state information report and the second channel state information report.

[0165] In some examples, the dominant layer indication component 750 may be configured to or otherwise support a unit for transmitting, to a base station, a precoding matrix indicator report including a layer indicator corresponding to the dominant spatial layer. In some examples, the dominant layer indication component 750 may be configured to or otherwise support a unit for transmitting, to a base station, a precoding matrix indicator report indicating that one or more layers are the dominant spatial layer, wherein the one or more layers are indicated based on a rank indicator of the precoding matrix indicator report. In some examples, the first channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

[0166] In some examples, the dominant layer update component 755 may be configured to or otherwise support units for determining an updated precoder for a dominant spatial layer. The dominant layer update component 755 may be configured to or otherwise support units for sending uplink control information to a base station to indicate the updated precoder for the dominant spatial layer, where an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0167] Figure 8 FIG. shows a system 800 including a device 805 that supports a layer-specific feedback period, in accordance with aspects of the present disclosure. The device 805 may be an example of or include components of the device 505, the device 605, or the UE 115 as described herein. The device 805 may wirelessly communicate with one or more base stations 105, UEs 115, or any combination thereof. The device 805 may include components for two-way voice and data communication, including components for sending and receiving communications, such as a communication manager 820, an input / output (I / O) controller 810, a transceiver 815, an antenna 825, a memory 830, code 835, and a processor 840. These components may communicate electronically via one or more buses (e.g., bus 845) or otherwise (e.g., operably, communicatively, functionally, electronically, electrically) coupled.

[0168] The I / O controller 810 may manage input and output signals for the device 805. The I / O controller 810 may also manage peripheral devices not integrated into the device 805. In some cases, the I / O controller 810 may represent a physical connection or port to an external peripheral device. In some cases, the I / O controller 810 may utilize an operating system, such as or another known operating system. Additionally or alternatively, the I / O controller 810 may represent a modem, a keyboard, a mouse, a touch screen, or similar device or interact with the foregoing devices. In some cases, the I / O controller 810 may be implemented as part of a processor (such as the processor 840). In some cases, a user may interact with the device 805 via the I / O controller 810 or via hardware components controlled by the I / O controller 810.

[0169] In some cases, device 805 may include a single antenna 825. However, in some other cases, device 805 may have more than one antenna 825 that can simultaneously transmit or receive multiple wireless transmissions. Transceiver 815 can communicate bidirectionally via one or more antennas 825, wired or wireless links as described herein. For example, transceiver 815 may represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 815 may also include a modem for modulating packets, providing the modulated packets to one or more antennas 825 for transmission, and demodulating packets received from one or more antennas 825. Transceiver 815 or transceiver 815 and one or more antennas 825 may be examples of transmitter 515, transmitter 615, receiver 510, receiver 610, or any combination thereof or components thereof as described herein.

[0170] Memory 830 may include random access memory (RAM) and read-only memory (ROM). Memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed by processor 840, cause device 805 to perform the various functions described herein. Code 835 may be stored in a non-transitory computer-readable medium (such as system memory or another type of memory). In some cases, code 835 may not be directly executable by processor 840 but may cause a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, in addition, memory 830 may also contain a basic input / output system (BIOS) that may control basic hardware or software operations, such as interactions with peripheral components or devices.

[0171] Processor 840 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 840 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 840. Processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 830) to cause device 805 to perform various functions (e.g., functions or tasks supporting layer-specific feedback cycles). For example, device 805 or components of device 805 may include processor 840 and memory 830 coupled to processor 840, and processor 840 and memory 830 are configured to perform the various functions described herein.

[0172] According to examples disclosed herein, communication manager 820 may support wireless communication at a UE. For example, communication manager 820 may be configured to or otherwise support a unit for receiving, from a base station, a channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, where the first feedback reporting period is different from the second feedback reporting period. Communication manager 820 may be configured to or otherwise support a unit for transmitting, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer. Communication manager 820 may be configured to or otherwise support a unit for transmitting, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer.

[0173] Additionally or alternatively, according to examples disclosed herein, communication manager 820 may support wireless communication at a UE. For example, communication manager 820 may be configured to or otherwise support a unit for receiving, from a base station, a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, where the first codebook is different from the second codebook. Communication manager 820 may be configured to or otherwise support a unit for transmitting, based on the second codebook, a first channel state information report for the non-dominant spatial layer. Communication manager 820 may be configured to or otherwise support a unit for receiving a first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer. Communication manager 820 may be configured to or otherwise support a unit for transmitting, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0174] By including or configuring communication manager 820 according to examples described herein, device 805 may support techniques for more efficient resource utilization. For example, by configuring different periods for the dominant spatial layer and the non-dominant spatial layer, UE 115 may report CSI for the dominant spatial layer less frequently. This may reduce the amount of overhead (e.g., resources used) at UE 115 for reporting CSI.

[0175] In some examples, communication manager 820 may be configured to perform various operations (e.g., receive, monitor, transmit) using transceiver 815, one or more antennas 825, or any combination thereof, or otherwise in cooperation with transceiver 815, one or more antennas 825, or any combination thereof. Although communication manager 820 is shown as a separate component, in some examples, one or more functions described with reference to communication manager 820 may be supported or performed by processor 840, memory 830, code 835, or any combination thereof. For example, code 835 may include instructions executable by processor 840 to cause device 805 to perform aspects of a layer-specific feedback loop as described herein, or processor 840 and memory 830 may otherwise be configured to perform or support such operations.

[0176] Figure 9 FIG. 900 is a block diagram illustrating a device 905 supporting a layer-specific feedback loop in accordance with aspects of the present disclosure. Device 905 may be an example of aspects of base station 105 as described herein. Device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. Device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0177] Receiver 910 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to a layer-specific feedback loop). The information may be passed to other components of device 905. Receiver 910 may utilize a single antenna or an array of multiple antennas.

[0178] Transmitter 915 may provide means for transmitting signals generated by other components of device 905. For example, transmitter 915 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to a layer-specific feedback loop). In some examples, transmitter 915 may be co-located with receiver 910 in a transceiver module. Transmitter 915 may utilize a single antenna or an array of multiple antennas.

[0179] Communication manager 920, receiver 910, transmitter 915, or various combinations or components thereof may be examples of means for performing aspects of a layer-specific feedback loop as described herein. For example, communication manager 920, receiver 910, transmitter 915, or various combinations or components thereof may support methods for performing one or more of the functions described herein.

[0180] In some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in hardware (e.g., with a communication management circuit). The hardware may include a processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured to or otherwise supporting units for performing the functions described in this disclosure. In some examples, a processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by the processor executing instructions stored in the memory).

[0181] Additionally or alternatively, in some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented with code executed by a processor (e.g., as communication management software or firmware). If implemented with code executed by a processor, the functions of the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination of these or other programmable logic devices (e.g., configured to or otherwise supporting units for performing the functions described in this disclosure).

[0182] In some examples, the communication manager 920 may be configured to use the receiver 910, the transmitter 915, or both, or otherwise cooperate with the receiver 910, the transmitter 915, or both to perform various operations (e.g., receive, monitor, transmit). For example, the communication manager 920 may receive information from the receiver 910, send information to the transmitter 915, or integrate in combination with the receiver 910, the transmitter 915, or both to receive information, send information, or perform various other operations as described herein.

[0183] According to examples disclosed herein, the communication manager 920 may support wireless communication at a base station. For example, the communication manager 920 may be configured to or otherwise support a unit for sending channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period. The communication manager 920 may be configured to or otherwise support a unit for receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period. The communication manager 920 may be configured to or otherwise support a unit for receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0184] Additionally or alternatively, in accordance with examples as disclosed herein, communication manager 920 may support wireless communication at a base station. For example, communication manager 920 may be configured to or otherwise support means for transmitting to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. Communication manager 920 may be configured to or otherwise support means for receiving, based on the second codebook, a first channel state information report for a non-dominant spatial layer. Communication manager 920 may be configured to or otherwise support means for transmitting first downlink control information that configures the UE to report channel state information for a dominant spatial layer and a non-dominant spatial layer. Communication manager 920 may be configured to or otherwise support means for receiving, based on the first codebook and the second codebook, a second channel state information report for a non-dominant spatial layer and a dominant spatial layer.

[0185] By including or configuring communication manager 920 in accordance with examples as described herein, device 905 (e.g., a processor controlling or otherwise coupled to receiver 910, transmitter 915, communication manager 920, or a combination thereof) may support techniques for more efficiently utilizing communication resources by reducing the rate of reporting CSI for a dominant spatial layer for both a periodic reporting scheme and an aperiodic CSI reporting scheme.

[0186] Figure 10 Block diagram 1000 illustrates device 1005 supporting layer-specific feedback periods in accordance with aspects of the present disclosure. Device 1005 may be an example of aspects of device 905 or base station 105 as described herein. Device 1005 may include receiver 1010, transmitter 1015, and communication manager 1020. Device 1005 may also include a processor. Each of these components may communicate with one another (e.g., via one or more buses).

[0187] Receiver 1010 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback periods). The information may be passed to other components of device 1005. Receiver 1010 may utilize a single antenna or an array of multiple antennas.

[0188] Transmitter 1015 may provide a unit for transmitting signals generated by other components of device 1005. For example, transmitter 1015 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to layer-specific feedback periods). In some examples, transmitter 1015 may be co-located with receiver 1010 in a transceiver module. Transmitter 1015 may utilize a single antenna or an array of multiple antennas.

[0189] Device 1005 or its various components may be examples of units for performing aspects of a layer-specific feedback period as described herein. For example, communication manager 1020 may include a CSI configuration sending component 1025, a dominant CSI reporting component 1030, a non-dominant CSI reporting component 1035, a dominant CSI reporting trigger component 1040, or any combination thereof. Communication manager 1020 may be an example of aspects of communication manager 920 as described herein. In some examples, communication manager 1020 or its various components may be configured to use receiver 1010, transmitter 1015, or both, or otherwise cooperate with receiver 1010, transmitter 1015, or both to perform various operations (e.g., receive, monitor, transmit). For example, communication manager 1020 may receive information from receiver 1010, send information to transmitter 1015, or integrate with receiver 1010, transmitter 1015, or both to receive information, send information, or perform various other operations as described herein.

[0190] According to examples disclosed herein, communication manager 1020 may support wireless communication at a base station. CSI configuration sending component 1025 may be configured to or otherwise support a unit for sending channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period. Dominant CSI reporting component 1030 may be configured to or otherwise support a unit for receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period. Non-dominant CSI reporting component 1035 may be configured to or otherwise support a unit for receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0191] Additionally or alternatively, according to examples as disclosed herein, communication manager 1020 may support wireless communication at a base station. The CSI configuration sending component 1025 may be configured to or otherwise support a unit for sending to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. The non-dominant CSI reporting component 1035 may be configured to or otherwise support a unit for receiving, based on the second codebook, a first channel state information report for a non-dominant spatial layer. The dominant CSI reporting trigger component 1040 may be configured to or otherwise support a unit for sending first downlink control information that configures the UE to report channel state information for a dominant spatial layer and a non-dominant spatial layer. The dominant CSI reporting component 1030 may be configured to or otherwise support a unit for receiving, based on the first codebook and the second codebook, a second channel state information report for a non-dominant spatial layer and a dominant spatial layer.

[0192] Figure 11 FIG. 1100 is a block diagram illustrating a communication manager 1120 that supports a layer-specific feedback period, in accordance with various aspects of the present disclosure. The communication manager 1120 may be an example of aspects of the communication manager 920, the communication manager 1020, or both as described herein. The communication manager 1120 or its various components may be examples of units for performing various aspects of a layer-specific feedback period as described herein. For example, the communication manager 1120 may include a CSI configuration sending component 1125, a dominant CSI reporting component 1130, a non-dominant CSI reporting component 1135, a dominant CSI reporting trigger component 1140, a CSI feedback component 1145, a dominant layer indication component 1150, a dominant layer update component 1155, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0193] According to examples as disclosed herein, communication manager 1120 may support wireless communication at a base station. The CSI configuration sending component 1125 may be configured to or otherwise support a unit for sending to a UE channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period. The dominant CSI reporting component 1130 may be configured to or otherwise support a unit for receiving, according to the first feedback reporting period, a first channel state information report for at least a dominant spatial layer. The non-dominant CSI reporting component 1135 may be configured to or otherwise support a unit for receiving, according to the second feedback reporting period, a second channel state information report for at least a non-dominant spatial layer.

[0194] In some examples, the CSI feedback component 1145 may be configured to or otherwise support a unit for sending downlink control information based on receiving a first channel state information report, where the downlink control information includes an acknowledgement feedback for the first channel state information report.

[0195] In some examples, the CSI configuration sending component 1125 may be configured to or otherwise support a unit for sending a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer.

[0196] In some examples, the first codebook is different from the second codebook.

[0197] In some examples, the dominant layer indicating component 1150 may be configured to or otherwise support a unit for receiving, from a UE, a precoding matrix indicator report including a layer indicator corresponding to a dominant spatial layer.

[0198] In some examples, the dominant layer indicating component 1150 may be configured to or otherwise support a unit for receiving, from a UE, a precoding matrix indicator report indicating that one or more spatial layers are dominant spatial layers, where the one or more spatial layers are indicated based on a rank indicator of the precoding matrix indicator report. In some examples, the number of the one or more spatial layers is based on the value of the rank indicator. In some examples, the first channel state information report includes channel quality information for non-dominant spatial layers and dominant spatial layers.

[0199] In some examples, the dominant layer updating component 1155 may be configured to or otherwise support a unit for receiving uplink control information from a UE, where the uplink control information indicates an updated precoder for a dominant spatial layer, and an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0200] Additionally or alternatively, according to examples as disclosed herein, the communication manager 1120 may support wireless communication at a base station. In some examples, the CSI configuration sending component 1125 may be configured to or otherwise support a unit for sending, to a UE, channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. In some examples, the non-dominant CSI reporting component 1135 may be configured to or otherwise support a unit for receiving, based on the second codebook, a first channel state information report for a non-dominant spatial layer. The dominant CSI reporting trigger component 1140 may be configured to or otherwise support a unit for sending first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer. In some examples, the dominant CSI reporting component 1130 may be configured to or otherwise support a unit for receiving, based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0201] In some examples, the dominant CSI reporting trigger component 1140 may be configured to or otherwise support a unit for sending second downlink control information to the UE that configures the UE to disable reporting channel state information for the dominant spatial layer.

[0202] In some examples, the CSI feedback component 1145 may be configured to or otherwise support a unit for sending downlink control information based on receiving the second channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report and the second channel state information report.

[0203] Figure 12 FIG. showing a system 1200 including a device 1205 that supports a layer-specific feedback period, in accordance with aspects of the present disclosure. The device 1205 may be an example of or include components of the device 905, the device 1005, or the base station 105 as described herein. The device 1205 may communicate wirelessly with one or more base stations 105, UEs 115, or any combination thereof. The device 1205 may include components for two-way voice and data communication, including components for sending and receiving communication, such as a communication manager 1220, a network communication manager 1210, a transceiver 1215, an antenna 1225, a memory 1230, code 1235, a processor 1240, and an inter-station communication manager 1245. These components may communicate electronically via one or more buses (e.g., bus 1250) or otherwise (e.g., operably, communicably, functionally, electronically, electrically) coupled.

[0204] The network communication manager 1210 may manage communication with the core network 130 (e.g., via one or more wired backhaul links). For example, the network communication manager 1210 may manage the transmission of data communication for client devices (e.g., one or more UEs 115).

[0205] In some cases, the device 1205 may include a single antenna 1225. However, in some other cases, the device 1205 may have more than one antenna 1225, which are capable of simultaneously transmitting or receiving multiple wireless transmissions. The transceiver 1215 may communicate bidirectionally via one or more antennas 1225, wired or wireless links as described herein. For example, the transceiver 1215 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1215 may also include a modem for modulating packets, providing the modulated packets to one or more antennas 1225 for transmission, and demodulating packets received from one or more antennas 1225. The transceiver 1215, or the transceiver 1215 and one or more antennas 1225, may be examples of the transmitter 915, transmitter 1015, receiver 910, receiver 1010 or any combination thereof or components thereof as described herein.

[0206] The memory 1230 may include RAM and ROM. The memory 1230 may store computer-readable, computer-executable code 1235 including instructions that, when executed by the processor 1240, cause the device 1205 to perform the various functions described herein. The code 1235 may be stored in a non-transitory computer-readable medium (such as system memory or other types of memory). In some cases, the code 1235 may not be directly executable by the processor 1240, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, in addition, the memory 1230 may also contain BIOS, which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0207] Processor 1240 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1240 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1230) to cause device 1205 to perform various functions (e.g., functions or tasks supporting layer-specific feedback cycles). For example, device 1205 or components of device 1205 may include processor 1240 and memory 1230 coupled to processor 1240, and processor 1240 and memory 1230 are configured to perform the various functions described herein.

[0208] The inter-station communication manager 1245 may manage communication with other base stations 105 and may include a controller or scheduler for collaboratively controlling communication with the UE 115 with other base stations 105. For example, the inter-station communication manager 1245 may coordinate the scheduling of transmissions to the UE 115 to implement various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communication manager 1245 may provide an X2 interface within the LTE / LTE-A wireless communication network technology to provide communication between base stations 105.

[0209] According to examples disclosed herein, communication manager 1220 may support wireless communication at a base station. For example, communication manager 1220 may be configured to or otherwise support a unit for sending a channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period. Communication manager 1220 may be configured to or otherwise support a unit for receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period. Communication manager 1220 may be configured to or otherwise support a unit for receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0210] Additionally or alternatively, according to an example as disclosed herein, the communication manager 1220 may support wireless communication at a base station. For example, the communication manager 1220 may be configured to or otherwise support a unit for transmitting to a UE channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. The communication manager 1220 may be configured to or otherwise support a unit for receiving, based on the second codebook, a first channel state information report for a non-dominant spatial layer. The communication manager 1220 may be configured to or otherwise support a unit for transmitting first downlink control information that configures the UE to report channel state information for a dominant spatial layer and a non-dominant spatial layer. The communication manager 1220 may be configured to or otherwise support a unit for receiving, based on the first codebook and the second codebook, a second channel state information report for a non-dominant spatial layer and a dominant spatial layer.

[0211] In some examples, the communication manager 1220 may be configured to use the transceiver 1215, one or more antennas 1225, or any combination thereof, or otherwise cooperate with the transceiver 1215, one or more antennas 1225, or any combination thereof to perform various operations (e.g., receive, monitor, transmit). Although the communication manager 1220 is shown as a separate component, in some examples, one or more functions described with reference to the communication manager 1220 may be supported or performed by the processor 1240, the memory 1230, the code 1235, or any combination thereof. For example, the code 1235 may include instructions executable by the processor 1240 to cause the device 1205 to perform aspects of a layer-specific feedback cycle as described herein, or the processor 1240 and the memory 1230 may otherwise be configured to perform or support such operations.

[0212] Figure 13 A flowchart illustrating a method 1300 for supporting a layer-specific feedback cycle in accordance with aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1300 may be performed by a UE 115 as described with reference to Figures 1 to 8 In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0213] At 1305, the method may include: receiving, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, where the first feedback reporting period is different from the second feedback reporting period. The operations of 1305 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1305 may be performed by the CSI configuration receiving component 725 as described with reference to 7.

[0214] At 1310, the method may include: transmitting, in accordance with the first feedback reporting period, a first channel state information report for at least the dominant spatial layer. The operations of 1310 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1310 may be performed by the dominant CSI reporting component 730 as described with reference to 7.

[0215] At 1315, the method may include: transmitting, in accordance with the second feedback reporting period, a second channel state information report for the non-dominant spatial layer. The operations of 1315 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1315 may be performed by the non-dominant CSI reporting component 735 as described with reference to 7.

[0216] Figure 14 A flowchart illustrating a method 1400 that supports layer-specific feedback periods in accordance with aspects of the present disclosure is shown. The operations of method 1400 may be implemented by a UE or components thereof as described herein. For example, the operations of method 1400 may be performed by a UE 115 as described with reference to Figures 1 to 8 described. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0217] At 1405, the method may include: receiving, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, where the first feedback reporting period is different from the second feedback reporting period. The operations of 1405 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1405 may be performed by the CSI configuration receiving component 725 as described with reference to 7.

[0218] At 1410, the method may include: sending, according to a first feedback reporting period, a first channel state information report for at least a dominant spatial layer. The operation of 1410 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1410 may be performed by the dominant CSI reporting component 730 as described with reference to 7.

[0219] At 1415, the method may include: sending, according to a second feedback reporting period, a second channel state information report for non-dominant spatial layers. The operation of 1415 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1415 may be performed by the non-dominant CSI reporting component 735 as described with reference to 7.

[0220] At 1420, the method may include: receiving downlink control information based on sending the first channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report. The operation of 1420 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1420 may be performed by the CSI feedback component 745 as described with reference to 7.

[0221] Figure 15 A flowchart illustrating a method 1500 that supports layer-specific feedback periods in accordance with aspects of the present disclosure is shown. The operations of method 1500 may be implemented by a UE or its components as described herein. For example, the operations of method 1500 may be performed by the UE 115 as described with reference to Figures 1 to 8 described. In some examples, the UE may execute an instruction set to control functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0222] At 1505, the method may include: sending to a base station a precoding matrix indicator report indicating that one or more spatial layers are dominant spatial layers, where the one or more spatial layers are indicated based on a rank indicator of the precoding matrix indicator report. The operation of 1505 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1505 may be performed by the dominant layer indicator component 750 as described with reference to 7.

[0223] At 1510, the method may include: receiving, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, where the first feedback reporting period is different from the second feedback reporting period. The operations of 1510 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1510 may be performed by the CSI configuration receiving component 725 as described with reference to 7.

[0224] At 1515, the method may include: sending, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer. The operations of 1515 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1515 may be performed by the dominant CSI reporting component 730 as described with reference to 7.

[0225] At 1520, the method may include: sending, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer. The operations of 1520 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1520 may be performed by the non-dominant CSI reporting component 735 as described with reference to 7.

[0226] Figure 16 A flowchart illustrating a method 1600 supporting layer-specific feedback periods in accordance with aspects of the present disclosure is shown. The operations of method 1600 may be implemented by a base station or its components as described herein. For example, the operations of method 1600 may be performed by the base station 105 as described with reference to Figures 1 to 4 and Figures 9 to 12 described. In some examples, the base station may execute an instruction set to control functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the described functions.

[0227] At 1605, the method may include: sending to a UE a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, where the first feedback reporting period is different from the second feedback reporting period. The operations of 1605 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1605 may be performed by the CSI configuration sending component 1125 as described with reference to 11.

[0228] At 1610, the method can include: receiving, according to a first feedback reporting period, a first channel state information report for at least a dominant spatial layer. The operation of 1610 can be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1610 can be performed by the dominant CSI reporting component 1130 as described with reference to 11.

[0229] At 1615, the method can include: receiving, according to a second feedback reporting period, a second channel state information report for at least a non-dominant spatial layer. The operation of 1615 can be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1615 can be performed by the non-dominant CSI reporting component 1135 as described with reference to 11.

[0230] Figure 17 A flowchart illustrating a method 1700 supporting layer-specific feedback periods in accordance with aspects of the present disclosure is shown. The operations of method 1700 can be implemented by a UE or its components as described herein. For example, the operations of method 1700 can be performed by the UE 115 as described with reference to Figures 1 to 8 described. In some examples, the UE can execute an instruction set to control functional elements of the UE to perform the described functions. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the described functions.

[0231] At 1705, the method can include: receiving, from a base station, a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook. The operation of 1705 can be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1705 can be performed by the CSI configuration receiving component 725 as described with reference to 7.

[0232] At 1710, the method can include: transmitting, based on the second codebook, a first channel state information report for a non-dominant spatial layer. The operation of 1710 can be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1710 can be performed by the non-dominant CSI reporting component 735 as described with reference to 7.

[0233] At 1715, the method can include: receiving first downlink control information that configures the UE to report channel state information for a dominant spatial layer and a non-dominant spatial layer. The operation of 1715 can be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1715 can be performed by the dominant CSI reporting trigger component 740 as described with reference to 7.

[0234] At 1720, the method may include: transmitting a second channel state information report for a non-dominant spatial layer and a dominant spatial layer based on a first codebook and a second codebook. The operations of 1720 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1720 may be performed by the dominant CSI reporting component 730 as described with reference to 7.

[0235] Figure 18 A flowchart illustrating a method 1800 supporting a layer-specific feedback period in accordance with aspects of the present disclosure is shown. The operations of method 1800 may be implemented by a base station or its components as described herein. For example, the operations of method 1800 may be performed by the base station 105 as described with reference to Figures 1 to 4 and Figures 9 to 12 described. In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the described functions.

[0236] At 1805, the method may include: transmitting to a UE a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, where the first codebook is different from the second codebook. The operations of 1805 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1805 may be performed by the CSI configuration transmitting component 1125 as described with reference to 11.

[0237] At 1810, the method may include: receiving a first channel state information report for a non-dominant spatial layer based on the second codebook. The operations of 1810 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1810 may be performed by the non-dominant CSI reporting component 1135 as described with reference to 11.

[0238] At 1815, the method may include: transmitting a first downlink control information that configures the UE to report channel state information for a dominant spatial layer and a non-dominant spatial layer. The operations of 1815 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1815 may be performed by the dominant CSI reporting triggering component 1140 as described with reference to 11.

[0239] At 1820, the method may include: receiving a second channel state information report for a non-dominant spatial layer and a dominant spatial layer based on the first codebook and the second codebook. The operations of 1820 may be performed in accordance with the examples disclosed herein. In some examples, aspects of the operations of 1820 may be performed by the dominant CSI reporting component 1130 as described with reference to 11.

[0240] The following provides a summary of aspects of the present disclosure:

[0241] Aspect 1: A method for wireless communication at a UE, comprising: receiving, from a base station, a channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; transmitting, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer; and transmitting, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer.

[0242] Aspect 2: The method according to aspect 1, further comprising: receiving downlink control information at least partially based on transmitting the first channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report.

[0243] Aspect 3: The method according to any one of aspects 1 to 2, wherein receiving the channel state information configuration comprises: receiving a channel state information configuration indicating a first codebook for the dominant spatial layer and a second codebook for the non-dominant spatial layer.

[0244] Aspect 4: The method according to aspect 3, wherein the first codebook is different from the second codebook.

[0245] Aspect 5: The method according to any one of aspects 1 to 4, further comprising: transmitting to the base station a precoding matrix indicator report including a layer indicator corresponding to the dominant spatial layer.

[0246] Aspect 6: The method according to any one of aspects 1 to 4, further comprising: transmitting to the base station a precoding matrix indicator report indicating that one or more spatial layers are dominant spatial layers, wherein the one or more spatial layers are indicated at least partially based on a rank indicator of the precoding matrix indicator report.

[0247] Aspect 7: The method according to aspect 6, wherein the number of the one or more spatial layers is at least partially based on the value of the rank indicator.

[0248] Aspect 8: The method according to any one of aspects 1 to 7, wherein the first channel state information report includes, at least partially based on the channel state information configuration, channel state information only for the dominant spatial layer or a full layer report for each spatial layer.

[0249] Aspect 9: The method according to any one of aspects 1 to 8, wherein the first channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

[0250] Aspect 10: The method according to any one of Aspects 1 to 9 further includes: determining an updated precoder for a dominant spatial layer; and transmitting uplink control information indicating the updated precoder for the dominant spatial layer to a base station, wherein an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0251] Aspect 11: The method according to any one of Aspects 1 to 10, wherein a first feedback reporting period for a non-dominant spatial layer is less than a second feedback reporting period for a dominant spatial layer.

[0252] Aspect 12: A method for wireless communication at a base station includes: transmitting channel state information configuration to a UE, the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; receiving a first channel state information report for at least the dominant spatial layer according to the first feedback reporting period; and receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

[0253] Aspect 13: The method according to Aspect 12 further includes: transmitting downlink control information at least partially based on receiving the first channel state information report, the downlink control information including an acknowledgment feedback for the first channel state information report.

[0254] Aspect 14: The method according to any one of Aspects 12 to 13 further includes: transmitting channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer.

[0255] Aspect 15: The method according to Aspect 14, wherein the first codebook is different from the second codebook.

[0256] Aspect 16: The method according to any one of Aspects 12 to 15 further includes: receiving a precoding matrix indicator report from the UE including a layer indicator corresponding to the dominant spatial layer.

[0257] Aspect 17: The method according to any one of Aspects 12 to 15 further includes: receiving a precoding matrix indicator report from the UE indicating that one or more spatial layers are dominant spatial layers, wherein the one or more spatial layers are indicated at least partially based on a rank indicator of the precoding matrix indicator report.

[0258] Aspect 18: The method according to Aspect 17, wherein the number of the one or more spatial layers is at least partially based on a value of the rank indicator.

[0259] Aspect 19: The method according to any one of Aspects 12 to 18, wherein the first channel state information report includes channel quality information for a non-dominant spatial layer and a dominant spatial layer.

[0260] Aspect 20: The method according to any one of Aspects 12 to 19, further comprising: receiving uplink control information from the UE, wherein the uplink control information indicates an updated precoder for the dominant spatial layer, and an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0261] Aspect 21: A method for wireless communication at a UE, comprising: receiving, from a base station, a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; transmitting, at least in part based on the second codebook, a first channel state information report for the non-dominant spatial layer; receiving first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and transmitting, at least in part based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0262] Aspect 22: The method according to Aspect 21, further comprising: receiving second downlink control information from the base station, the second downlink control information configuring the UE to disable reporting channel state information for the dominant spatial layer.

[0263] Aspect 23: The method according to any one of Aspects 21 to 22, further comprising: receiving downlink control information, at least in part based on transmitting the second channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report and the second channel state information report.

[0264] Aspect 24: The method according to any one of Aspects 21 to 23, further comprising: transmitting to the base station a precoding matrix indicator report including a layer indicator corresponding to the dominant spatial layer.

[0265] Aspect 25: The method according to any one of Aspects 21 to 23, further comprising: transmitting to the base station a precoding matrix indicator report indicating that one or more layers are dominant spatial layers, wherein the one or more layers are indicated at least in part based on a rank indicator of the precoding matrix indicator report.

[0266] Aspect 26: The method according to any one of Aspects 21 to 25, wherein the first channel state information report includes channel quality information for a non-dominant spatial layer and a dominant spatial layer.

[0267] Aspect 27: The method according to any one of Aspects 21 to 26 further includes: determining an updated precoder for the dominant spatial layer; and sending uplink control information to a base station to indicate the updated precoder for the dominant spatial layer, wherein an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

[0268] Aspect 28: A method for wireless communication at a base station includes: sending channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer to a UE, wherein the first codebook is different from the second codebook; receiving, at least in part based on the second codebook, a first channel state information report for the non-dominant spatial layer; sending first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and receiving, at least in part based on the first codebook and the second codebook, a second channel state information report for the non-dominant spatial layer and the dominant spatial layer.

[0269] Aspect 29: The method according to Aspect 28 further includes: sending second downlink control information to the UE that configures the UE to disable reporting of channel state information for the dominant spatial layer.

[0270] Aspect 30: The method according to any one of Aspects 28 to 29 further includes: sending downlink control information at least in part based on receiving the second channel state information report, the downlink control information including an acknowledgement feedback for the first channel state information report and the second channel state information report.

[0271] Aspect 31: An apparatus for wireless communication at a UE includes: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to any one of Aspects 1 to 11.

[0272] Aspect 32: An apparatus for wireless communication at a UE includes at least one unit for performing the method according to any one of Aspects 1 to 11.

[0273] Aspect 33: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code including instructions executable by a processor to perform the method according to any one of Aspects 1 to 11.

[0274] Aspect 34: An apparatus for wireless communication at a base station includes: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to any one of Aspects 12 to 20.

[0275] Aspect 35: An apparatus for wireless communication at a base station, comprising at least one unit for performing the method according to any one of Aspects 12 to 20.

[0276] Aspect 36: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method according to any one of Aspects 12 to 20.

[0277] Aspect 37: An apparatus for wireless communication at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to any one of Aspects 21 to 17.

[0278] Aspect 38: An apparatus for wireless communication at a UE, comprising at least one unit for performing the method according to any one of Aspects 21 to 27.

[0279] Aspect 39: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform the method according to any one of Aspects 21 to 27.

[0280] Aspect 40: An apparatus for wireless communication at a base station, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to any one of Aspects 28 to 30.

[0281] Aspect 41: An apparatus for wireless communication at a base station, comprising at least one unit for performing the method according to any one of Aspects 28 to 30.

[0282] Aspect 42: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method according to any one of Aspects 28 to 30.

[0283] It should be noted that the methods described herein describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are possible. In addition, aspects from two or more methods can be combined.

[0284] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for purposes of example, and the LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to a variety of other wireless communication systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0285] The information and signals described herein may be represented using any of a variety of different technologies and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0286] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general purpose processor, DSP, ASIC, CPU, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0287] 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 via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these items. The features implementing the functions may also be physically located at various positions, including being distributed such that portions of the functions are implemented at different physical locations.

[0288] A computer-readable medium includes both a non-transitory computer storage medium and a communication medium, where the communication medium includes any medium that facilitates transfer of a computer program from one place to another. The non-transitory storage medium can be any available medium that can be accessed by a general-purpose or a special-purpose computer. By way of example, and not limitation, the non-transitory computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store the desired program code units in the form of instructions or data structures and that can be accessed by a general-purpose or a special-purpose computer, or a general-purpose or a special-purpose processor. In addition, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable medium.

[0289] As used herein (including in the claims), the "or" as used in a list of items (e.g., a list of items that ends with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, such that a list of, for example, at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0290] In the figures, similar components or features may have the same reference numeral. Additionally, various components of the same type can be distinguished by following the reference numeral with a dash and a second label used to differentiate among similar components. If only the first reference numeral is used in the specification, the description applies to any one of the similar components having the same first reference numeral, regardless of the second reference numeral or any other subsequent reference numerals.

[0291] The description of example configurations is provided in the context of the descriptions presented in conjunction with the accompanying drawings and is not intended to represent all examples that can be implemented or that are within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration" and not "preferred" or "advantageous over other examples." For the purpose of providing an understanding of the described technology, the detailed description includes specific details. However, the technology may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0292] The description provided herein enables a person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: Receiving, from a base station, a channel state information configuration that indicates a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; Sending, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer; and Sending, according to the second feedback reporting period, a second channel state information report for the non-dominant spatial layer.

2. The method according to claim 1, further comprising: Receiving downlink control information at least partially based on sending the first channel state information report, the downlink control information including an acknowledgment feedback for the first channel state information report.

3. The method according to claim 1, wherein Receiving the channel state information configuration includes: Receiving the channel state information configuration that indicates a first codebook for the dominant spatial layer and a second codebook for the non-dominant spatial layer.

4. The method according to claim 3, wherein The first codebook is different from the second codebook.

5. The method according to claim 1, further comprising: Sending a precoding matrix indicator report to the base station that includes a layer indicator corresponding to the dominant spatial layer.

6. The method according to claim 1, further comprising: Sending a precoding matrix indicator report to the base station that indicates that one or more spatial layers are dominant spatial layers, wherein the one or more spatial layers are indicated at least partially based on a rank indicator of the precoding matrix indicator report.

7. The method according to claim 6, wherein, The number of the one or more spatial layers is at least partially based on the value of the rank indicator.

8. The method according to claim 1, wherein The first channel state information report includes, at least partially based on the channel state information configuration, channel state information only for the dominant spatial layer or a full-layer report for each spatial layer.

9. The method according to claim 1, wherein, The second channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

10. The method according to claim 1, further comprising: Determining an updated precoder for the dominant spatial layer; and And Sending uplink control information to the base station that indicates the updated precoder for the dominant spatial layer, wherein an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

11. The method according to claim 1, wherein, The second feedback reporting period for the non-dominant spatial layer is less than the first feedback reporting period for the dominant spatial layer.

12. A method for wireless communication at a base station, comprising: Sending a channel state information configuration to a user equipment (UE), the channel state information configuration indicating a first feedback reporting period for a dominant spatial layer and a second feedback reporting period for a non-dominant spatial layer, wherein the first feedback reporting period is different from the second feedback reporting period; Receiving, according to the first feedback reporting period, a first channel state information report for at least the dominant spatial layer; and Receiving a second channel state information report for at least the non-dominant spatial layer according to the second feedback reporting period.

13. The method according to claim 12, further comprising: Transmitting downlink control information at least partially based on receiving the first channel state information report, the downlink control information including an acknowledgment feedback for the first channel state information report.

14. The method according to claim 12, further comprising: Transmitting the channel state information configuration indicating a first codebook for the dominant spatial layer and a second codebook for the non-dominant spatial layer.

15. The method according to claim 14, wherein, The first codebook is different from the second codebook.

16. The method according to claim 12, further comprising: Receiving a precoding matrix indicator report from the UE including a layer indicator corresponding to the dominant spatial layer.

17. The method according to claim 12, further comprising: Receiving a precoding matrix indicator report from the UE indicating that one or more spatial layers are dominant spatial layers, wherein the one or more spatial layers are indicated at least partially based on a rank indicator of the precoding matrix indicator report.

18. The method according to claim 17, wherein, The number of the one or more spatial layers is at least partially based on the value of the rank indicator.

19. The method according to claim 12, wherein, The second channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

20. The method according to claim 12, further comprising: Receiving uplink control information from the UE, wherein the uplink control information indicates an updated precoder for the dominant spatial layer, and an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

21. A method for wireless communication at a user equipment (UE), comprising: Receiving from a base station a channel state information configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; Transmitting a first channel state information report for the non-dominant spatial layer at least partially based on the second codebook; Receiving first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and In response to the first downlink control information, transmitting a second channel state information report for the non-dominant spatial layer and the dominant spatial layer at least partially based on the first codebook and the second codebook.

22. The method according to claim 21, further comprising: Receiving second downlink control information from the base station that configures the UE to disable reporting of channel state information for the dominant spatial layer.

23. The method according to claim 21, further comprising: Receiving third downlink control information at least partially based on transmitting the second channel state information report, the third downlink control information including an acknowledgment feedback for the first channel state information report and the second channel state information report.

24. The method according to claim 21 further comprises: Sending a precoding matrix indicator report to the base station, the report including a layer indicator corresponding to the dominant spatial layer.

25. The method according to claim 21 further comprises: Sending a precoding matrix indicator report to the base station, the report indicating that one or more layers are dominant spatial layers, wherein the one or more layers are indicated at least in part based on a rank indicator of the precoding matrix indicator report.

26. The method according to claim 21, wherein, The first channel state information report includes channel quality information for the non-dominant spatial layer and the dominant spatial layer.

27. The method according to claim 21 further comprises: Determining an updated precoder for the dominant spatial layer; And Sending uplink control information to the base station to indicate the updated precoder for the dominant spatial layer, wherein an indicator in the uplink control information indicates that the updated precoder is included in the uplink control information.

28. A method for wireless communication at a base station, comprising: Sending channel state information configuration to a user equipment (UE), the configuration indicating a first codebook for a dominant spatial layer and a second codebook for a non-dominant spatial layer, wherein the first codebook is different from the second codebook; Receiving a first channel state information report for the non-dominant spatial layer at least in part based on the second codebook; Sending first downlink control information that configures the UE to report channel state information for the dominant spatial layer and the non-dominant spatial layer; and Receiving a second channel state information report for the non-dominant spatial layer and the dominant spatial layer at least in part based on the first codebook and the second codebook in response to the first downlink control information.

29. The method according to claim 28 further comprises: Sending second downlink control information to the UE, the second downlink control information configuring the UE to disable reporting of channel state information for the dominant spatial layer.

30. The method according to claim 28 further comprises: Sending third downlink control information at least in part based on receiving the second channel state information report, the third downlink control information including an acknowledgement feedback for the first channel state information report and the second channel state information report.

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