Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may select, from a set of demodulation reference signal (DMRS) configurations, a recommended DMRS configuration for a downlink communication, the recommended DMRS configuration associated with a set of DMRS parameters; and transmit an indication of the recommended DMRS configuration. Numerous other aspects are provided.

Abstract: Aspects are provided which allow for a base station to transmit code blocks according to a frequency first per layer (FFPL) mapping, and for a UE to decode received code blocks according to the FFPL mapping. The base station maps a plurality of code blocks to multiple layers, where each of the code blocks is mapped to a plurality of resource elements initially by frequency and subsequently by time on only a single layer of the multiple layers. The base station then transmits data including the code blocks to a UE. Afterwards, the UE receives the data including the mapped code blocks in multiple layers from the base station, and the UE decodes the code blocks based on the mapping. Thus, improvements in link efficiency, reliability, and reduced power consumption compared to frequency first (FF) mapping approaches may be achieved.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a transport block (TB), the receiving the TB including performing log likelihood ratio (LLR) calculations on one or more parts of the TB based at least in part on a determination that the TB is likely to fail a cyclic redundancy check (CRC). The UE may transmit an indication of the one or more parts of the TB for which the UE performed LLR calculations. Numerous other aspects are described.

Abstract: Aspects relate to techniques for a user equipment (UE) to report a demodulator type associated with a negative acknowledgement (NACK) to a base station. The UE may provide an indicator of the demodulator type utilized by the UE in demodulating an initial transmission of a transport block within feedback information including a NACK associated with the initial transmission. The base station may transmit a retransmission of the transport block based on the NACK and the demodulator type.

Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may determine a set of groups of layers relating to a set of transport blocks (TBs) or a set of code division multiplexing (CDM) groups. The UE may group the layers such that the layers in each group have a minimal difference in signal-to-interference-plus-noise ratio (SINR) between the layers. The UE may select a different demodulation reference signal (DMRS) configuration for each of the set of groups of layers based on maximizing a communication efficiency metric for each group of layers. The UE may transmit an indication of the selected DMRS configurations for each group of layers to a base station via a field in a report. The base station may accordingly determine a DMRS configuration for each group of layers based on the DMRS configurations indicated by the UE.

Abstract: Certain aspects of the present disclosure provide techniques for wireless communications by a user equipment (UE). The UE implements the technique to transmit to a network entity a report that includes an indication of a desired demodulator or precoding per precoding resource block group (PRG) for a group of one or more PRGs. The UE then demodulates downlink (DL) transmissions, transmitted from the network entity on the group of one or more PRGs, in accordance with the indication included in the report.

Abstract: Apparatus, methods, and computer program products for improving precoding downlink signaling are provided. An example method may include determining one or more noise covariance parameters for a noise covariance report, the noise covariance parameters being associated with a noise covariance matrix for whitening. The example method further may include transmitting, to a base station, the noise covariance report including the one or more noise covariance parameters or a noise whitening matrix for the whitening, the noise covariance report being transmitted based on a transmission periodicity of one or more slots.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to a base station, a report that indicates a phase tracking reference signal (PTRS) density for a PTRS. The UE may receive, from the base station via a downlink shared channel, the PTRS in accordance with the PTRS density based at least in part on the report. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. Generally, the described techniques provide for flexible selection of a type of mapping to use for mapping code blocks to a set of resources for transmission. A user equipment (UE) may transmit assistance information to a base station to assist the base station in selecting from a set of mapping types available for code block mapping. The UE may then receive, from the base station, an indication of a selected mapping type for code block mapping based on the assistance information. The assistance information may include a recommendation of a mapping type or a metric of a channel that the base station may use to select the mapping type. Because the mapping type may be selected dynamically (e.g., “on the fly”), the UE and the base station may be able to adaptively exploit different types of diversity.

Abstract: A user equipment may be configured to perform demodulator selection based on ML model coefficients trained by a base station. In some aspects, the user equipment may transmit a dynamic demodulator indication to a base station, transmit channel information to the base station, and receive, in response to the dynamic demodulator indication, updated coefficient information based on the channel information. Further, the user equipment may select a demodulator based on the updated coefficient information, and communicate with the base station via the demodulator in response to the selection of the demodulator.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device (e.g., a user equipment (UE) or base station) may reduce a peak to average power ratio (PAPR) by clipping signals transmitted to a receiving device according to a clipping level. The receiving device may receive, from the transmitting device, an indication of the clipping level associated with a reference signal. The receiving device may receive the reference signal and identify distortions based on the clipping level. The receiving device may iteratively reconstruct peaks of the clipped reference signal until the receiving device is able to obtain accurate pilot symbols for use in channel estimation. The techniques described herein may enable receiving devices to improve efficiency and reliability of communications by improving channel estimation, which may increase the probability of successfully decoding transmitted information.

Abstract: Aspects described herein relate to configuring a search space size for a demodulator to use in generating log likelihood ratios (LLRs) in demodulating received signals. In an aspect, an indication of a search space size for a demodulator to use in generating LLRs can be received from a base station, and a demodulation of one or more signals received in wireless communication can be performed by a node using the demodulator and based on the search space size. In another aspect, a search space size for the demodulator of the node to use in generating log likelihood ratios (LLRs) can be determined based on one or more signals transmitted by the node, and an indication of a search space size can be transmitted to the node.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit an indication of a demodulator configuration to a user equipment (UE) for the UE to use that demodulator configuration for demodulating a multi-layer transmission from the base station. The base station may determine the demodulator configuration for the UE to use based on one or more uplink signals transmitted from the UE. Additionally, the UE may transmit an indication of demodulator capabilities that the UE supports to the base station, where the base station determines the demodulator configuration based on the indication of the demodulator capabilities. In some examples, the demodulator configuration may indicate a demodulation search space corresponding to a number of layers included per layer group of the multi-layer transmission, may correspond to an amount of cross correlation determined between respective layers of the multi-layer transmission, or a combination thereof.

Abstract: Certain aspects of the present disclosure provide techniques for wireless communications by a user equipment (UE). The UE implements the technique to transmit to a network entity a report that includes an indication of a desired demodulator or precoding per precoding resource block group (PRG) for a group of one or more PRGs. The UE then demodulates downlink (DL) transmissions, transmitted from the network entity on the group of one or more PRGs, in accordance with the indication included in the report.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication of a requested periodicity for uplink reference signals associated with improving UE power efficiency. The UE may receive an indication of resources for transmitting uplink reference signals based at least in part on the requested periodicity. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. In a wireless communications system, a user equipment (UE) may be configured to use intra-message antenna selection diversity (ASD). The UE may transmit a first portion of a scheduled message within a time interval using a first antenna element of the UE based on an intra-message antenna diversity configuration. The intra-message antenna diversity configuration may indicate a set of antennas available for transmission of the scheduled message. In some cases, the UE may transmit, within the same time interval, at least a portion of the scheduled message using at least a second antenna element of the UE that is different from the first antenna element. In some cases, a receiving UE may decode the first portion and the second portion of the scheduled message based on the intra-message antenna diversity configuration.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a transmitter, a reference signal block provided based at least in part on an orthogonal frequency division multiplexing (OFDM) waveform. The UE may perform an estimation operation based at least in part on the reference signal block. The UE may receive a data transmission via a single carrier waveform based at least in part on the estimation operation. Numerous other aspects are provided.

Abstract: Aspects described herein relate to configuring a search space size for a demodulator to use in generating log likelihood ratios (LLRs) in demodulating received signals. In an aspect, an indication of a search space size for a demodulator to use in generating LLRs can be received from a base station, and a demodulation of one or more signals received in wireless communication can be performed by a node using the demodulator and based on the search space size. In another aspect, a search space size for the demodulator of the node to use in generating log likelihood ratios (LLRs) can be determined based on one or more signals transmitted by the node, and an indication of a search space size can be transmitted to the node.

Abstract: Apparatus, methods, and computer program products for improving precoding downlink signaling are provided. An example method may include determining one or more noise covariance parameters for a noise covariance report, the noise covariance parameters being associated with a noise covariance matrix for whitening. The example method further may include transmitting, to a base station, the noise covariance report including the one or more noise covariance parameters or a noise whitening matrix for the whitening, the noise covariance report being transmitted based on a transmission periodicity of one or more slots.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, in a slot, a preamble provided based at least in part on an orthogonal frequency division multiplexing (OFDM) waveform. The UE may perform an estimation operation based at least in part on the preamble. The UE may receive, in the slot, a data transmission via a single carrier time-domain waveform based at least in part on the estimation operation. Numerous other aspects are provided.