Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit, and a user equipment (UE) may receive, a sounding reference signal (SRS) configuration that indicates a reference group among multiple antenna groups of an antenna array associated with the UE. The UE may transmit an SRS using one or more antennas in the reference group. The UE may transmit, to the base station, a correlation report that indicates an inter-group correlation between the multiple antenna groups associated with the UE. The base station may estimate a channel matrix for the multiple antenna groups based at least in part on the inter-group correlation and measurements of the SRS that is transmitted using the one or more antennas in the reference group. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive. from a base station, signaling that indicates an indirect assignment of a slot for transmitting sounding reference signals (SRSs) in multiple SRS resource sets. The UE may determine whether the slot is available for the indirect assignment based on a first set of characteristics associated with the multiple SRS resource sets and a second set of characteristics associated with the slot. If the UE determines that the slot is available for the indirect assignment, the UE may transmit SRSs in the multiple SRS resource sets during the slot. If the UE determines that the slot is unavailable for the indirect assignment. the UE may refrain from transmitting SRSs in one or more of the multiple SRS resource sets during the slot.

Abstract: Methods, systems, and devices for wireless communications are described. For instance, a user equipment (UE) may receive. from a base station, control signaling for a first sounding reference signal. The UE may determine, based on the configuration and a set of parameters associated with partial frequency sounding of the first sounding reference signal, a subset of a set of re sources configured for the first sounding reference signal, where the subset of the set of resources excludes at least one resource of the set of resources. The UE may transmit, to the base station, a second sounding reference signal over the subset of the set of resources.

Abstract: Methods, systems, and devices for wireless communications are described. The method includes receiving, from a base station, control information identifying a configuration for transmission of an aperiodic sounding reference signal, receiving, from the base station, a downlink control message including a set of one or more blocks, where each block of the one or more blocks includes a sounding reference signal request in accordance with the configuration for transmission of an aperiodic sounding reference signal, an indication of an available slot corresponding to that block, and one or more transmit power control commands, and transmitting, during the available slot corresponding to a block of the set of one or more blocks, the aperiodic sounding reference signal in accordance with a power level indicated by the one or more transmit power control commands corresponding to the block.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify one or more antenna groups at the UE, each of the one or more antenna groups comprising two or more antenna ports and associated with group-based sounding reference signal transmission. The UE may receive an indication of a sounding reference signal configuration identifying one or more resources for performing group-based sounding reference signal transmissions using at least one of the one or more antenna groups. The UE may transmit one or more sounding reference signals using the one or more resources and at least one antenna port from the at least one of the one or more antenna groups.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, configuration information regarding one or more available slots associated with transmitting sounding reference signal (SRS) information. The UE may receive, from the base station, dynamic downlink communication including slot information for determining a select available slot from among the one or more available slots. The UE may transmit, to the base station, the SRS information during the select available slot, determined based at least in part on the slot information and the configuration information. Numerous other aspects are described.

Abstract: A first device may select a base graph from a plurality of base graphs based on one or more of (a) a decoding complexity of a second device, (b) a device category of the second device, (c) a capability of the second device, (d) a decoder mode of the second device, (e) a receiver complexity of the second device, (f) a receiver mode of the second device, (g) a power consumption of the second device, (h) a power mode of the second device, or (i) an indication from the second device. The first device may output an LDPC coded transmission to the second device based on the selected base graph.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, control signaling indicating a configuration for use by the UE to select one or more of a plurality of resource sets for a bandwidth part (BWP) for the UE, where each of the resource sets comprise reference signal resources that correspond to one or more antenna ports of the UE. The UE may receive, from the base station, an activation message instructing the UE to activate at least one resource set of the plurality of resource sets for reference signal transmission using the BWP. The UE may transmit a reference signal over the activated resource set using the BWP and at least one antenna port of the one or more antenna ports based at least in part on the activation message, the antenna port corresponding to the activated resource set.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information including a sounding reference signal (SRS) configuration associated with configured SRS resources. The UE may receive a medium access control (MAC) control element (MAC CE) or downlink control information (DCI) including reconfiguration information associated with the SRS resources. The UE may transmit, based at least in part on the reconfiguration information, SRS information including select SRS resources, selected from among the configured SRS resources, utilizing select SRS ports. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. The described techniques provide for a base station using antenna groups configured at a user equipment (UE) for CSI reporting. The base station may transmit an indication of the antenna group that the UE is to use for measuring and reporting CSI. Based on the received indication, the UE may measure a reference signal transmitted by the base station and received at the UE using one or more antennas of the antenna group in accordance with the indication. The UE may transmit, to the base station, a CSI report that is based on the measuring of the reference signal using the one or more antennas of the antenna group.

Abstract: A user equipment may be configured to assist channel reconstruction using partial spatial sounding. In some aspects, the user equipment (UE) may transmit, to another device, correlation capability information indicating a sounding reference signal (SRS) grouping capability of the UE, and receive, from the other device, reference signal (RS) configuration information for configuring a sounding procedure to be performed by the UE. Further, the UE may transmit a reference signal to the other device over a reference antenna port of the UE to allow the other device to determine channel information for another antenna port of the UE, and receive data from the other device based on the channel information.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a mobile station may receive a medium access control (MAC) control element (MAC CE) indicating a MAC CE configuration associated with a sounding reference signal (SRS) resource. The mobile station may receive downlink control information (DCI) indicating a DCI configuration associated with the SRS resource. The mobile station may selectively transmit SRS information associated with the SRS resource based at least in part on a time of receipt of the MAC CE. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission that exceeds the first number of one or more transmit antennas. The UE may receive, based on the capability message, a sounding reference signal (SRS) configuration indicating a mapping between each SRS resource or SRS resource group and a respective bit sequence of a set of bit sequences. The UE may receive a control message comprising one or more bit sequences of the set of bit sequences indicating one or more SRS resources or an SRS resource group based on the mapping. The UE may transmit one or more SRS signals based on the control message.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information that configures a reference signal (RS) transmission with a repetition factor, wherein the configuration information indicates one or more parameters for the RS transmission including at least one of: a sequence hopping configuration associated with the RS transmission, a cyclic shift offset configuration associated with the RS transmission, or a frequency hopping configuration indicating subcarrier hopping across adjacent RS symbols. The UE may perform the RS transmission using the repetition factor in accordance with the configuration. Numerous other aspects are described.

Abstract: Aspects of the present disclosure provide various devices, methods, and systems for dynamic spectrum sharing of a spectrum between different radio access technologies and multiple frequency division duplexing modes. Dynamic spectrum sharing (DSS) is a technology that allows wireless network operators to share a spectrum between different radio access technologies (RATs). DSS allows an operator to dynamically allocate some existing 4G spectrum to 5G use to deliver 5G services using a shared spectrum.

Abstract: Methods, systems, and devices for wireless communications are described. Generally, the described techniques provide for a device such as a user equipment (UE), a base station, or both, to perform a channel noise and interference estimation based on a set of null resources in a data channel. The device may identify a first configuration for a set of demodulation reference signals (DMRSs) in a first set of time periods of a data channel and a second configuration for a set of null resources in a second set of time periods of the data channel. The second set of time periods may be nonoverlapping with the first set of time periods. The device may perform a channel estimation procedure on the data channel based on the null resources and the DMRS resources. The device may process data received via resources of the data channel based on the channel estimation procedure.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may receive a capability message from a user equipment (UE) based on a number of receive antennas exceeding a number of transmit antennas at the UE. The base station may configure the UE with a mapping between sounding reference signal (SRS) resources and bit sequences, or SRS resource indices (SRIs), based on the capability message. The base station may transmit a control message including one or more SRIs indicating respective SRS resources. The UE may use the one or more SRIs included in a control message from the base station to select respective SRS resources from a resource set. Once the UE selects one or more SRS resources, the UE may transmit one or more SRSs in the SRS resources.

Abstract: A method and device for transmitting reference signals are provided in the present disclosure, where the method for transmitting reference signals is performed by a user terminal and time-frequency resources for the user terminal are divided into multiple groups of time-frequency resources. The method includes: selecting a reference signal port for each group of time-frequency resources from candidate reference signal ports; and transmitting reference signals by using the reference signal port corresponding to each group of time-frequency resources.

Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may transmit, to a base station, a UE capability message indicating support for at least a first demodulation mode or a second demodulation mode. The first demodulation mode may correspond to a single demodulation procedure associated with a set of antenna ports at the UE, and the second demodulation mode may correspond to multiple demodulation procedures, each procedure associated with a respective subset of antenna ports at the UE. In some cases, the UE may flexibly switch between demodulation modes. The UE may receive, from the base station, one or more downlink signals via one or more downlink beams based on the indication of the first demodulation mode or the second demodulation mode. The UE may demodulate the one or more downlink signals based on the indicated (e.g., an active) demodulation mode.

Abstract: Aspects relate to configuring active groups of antenna ports. An apparatus may support different groups of antenna ports. One or more of these groups may be designated as active (e.g., for a scheduled transmission). In some examples, a first apparatus may send to a second apparatus an indication of the active groups. The second apparatus may then use the active groups for a transmission.