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: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit, to a base station, a request for a data transmission that includes multiple subsets of data each associated with a different constellation granularity. In response to the request, the base station may encode the data transmission using multiple different constellation granularities and may transit the encoded data transmission to the UE. For example, the UE may receive the data transmission including a first subset of data that was encoded by the base station using a first constellation granularity and a second subset of data that was encoded by the base station using a second constellation granularity. The UE may then iteratively estimate phase-noises associated with respective subsets of data and perform phase-noise correction operations on the entire data transmission based on the estimated phase-noises.

Abstract: A phase tracking reference signal (PTRS) may be enhanced to carry data encoded with a relative low modulation and coding scheme (MCS). A receive device may receiving a data channel, the data channel including a transport block encoded using a first MCS. The receiving device may receiving a PTRS interleaved with the data channel. The PTRS is encoded with the second MCS that is lower than the first MCS. The receiving device may decode the PTRS to determine PTRS data. The receiving device may track phase noise using the PTRS data as a transmitted sequence of the PTRS. The receiving device may decode the transport block for the data channel based on the first MCS and the tracked phase noise.

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: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive one or more reference signals associated with a downlink communication. The UE may transmit an indication of a preferred demodulation reference signal (DMRS) configuration to be used for the downlink communication, the preferred DMRS configuration based at least in part on the one or more reference signals and a transmission mode associated with the preferred DMRS configuration. Numerous other aspects are described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication associated with phase noise characteristics of the UE. The UE may receive an indication of pilot allocation sizes, for different data modulation and coding schemes (MCSs) for communications, of frequency-domain contiguous pilots for phase noise mitigation based at least in part on the indication associated with the phase noise characteristics of the UE. Numerous other aspects are described.

Abstract: Certain aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for phase noise (PN) mitigation on multiple component carriers (CCs). A method that may be performed by a user equipment (UE) includes estimating impairments (e.g., common phase error (CPE) and/or inter-carrier interference (ICI)) caused by PN for only a first CC configured for the UE, wherein the first CC is configured with pilots for PN mitigation and mitigating the PN on each CC for all CCs configured for the UE based, at least in part, on the estimated impairments for the first CC.

Abstract: An apparatus for wireless communication includes a transmitter and a receiver. The receiver is configured to receive a first code block (CB) that is associated with a code block group (CBG) and that is included in a transport block (TB). The receiver is further configured to receive a second CB that is associated with the CBG and that is included in the TB. The first CB is distinct from the second CB. The second CB includes at least a first bit that is associated with the first CB.

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: Methods, systems, and devices for wireless communications are described that support a single carrier multi-level coding (MLC) amplitude phase shift keying (APSK) modulated waveform. For example, a user equipment (UE) capable to communicate using MLC APSK modulated waveforms may transmit a channel state information (CSI) report, including a recommendation for a waveform configuration, to a base station. The base station may receive the CSI report and may transmit a configuration message to the UE, which may configure the UE with a set of waveform parameters associated with MLC APSK modulation. The UE may receive the configuration message and may communicate with the base station using MLC APSK modulated waveforms and based on the set of waveform parameters, which may reduce phase noise and provide lower peak average power ratio (PAPR) signaling.

Abstract: A base station may configure a Doppler tracking sounding reference signal (SRS) resource set with different time gaps between SRS resources of the Doppler tracking SRS resource set. However, factors influencing an optimal time gap for uplink Doppler parameter estimation may change over time and may depend on a Doppler parameter to be estimated. Therefore, parameters of an aperiodic Doppler tracking SRS resource set configuration may become suboptimal for estimating uplink Doppler parameters. Some techniques and apparatuses described herein enable dynamic parameter adaptation for aperiodic Doppler tracking SRS resource sets. The base station may dynamically adapt one or more parameters for an aperiodic Doppler tracking SRS resource set to modify a time gap and/or a number of resources or symbols to be transmitted for an aperiodic Doppler tracking SRS resource set. The base station may transmit downlink control information that indicates the one or more parameters.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) receives control signaling from the base station indicating a set of transmission mode indicators or transmission mode options and a set of demodulation reference signal (DMRS) configurations for every transmission mode from a set of transmission modes. The base station transmits additional control signaling to dynamically indicate a transmission mode or a combination of transmission mode indicators and DMRS configuration parameters to signal the transmission mode and one or more associated DMRS configurations. The UE identifies a DMRS configuration and a transmission mode based on the additional control signaling. The UE receives one or more DMRSs from multiple transmission reception points (TRPs) based on the joint/disjoint DMRS and transmission mode signaling. The UE receives one or more data messages from the TRPs based on the transmission mode indication and based on the received DMRSs.

Abstract: Methods, systems, and devices for wireless communications are described. A base station communicates with a UE via transmission reception points (TRPs). A UE receives, from a base station, control signaling identifying a set of demodulation reference signal (DMRS) configurations. The UE receives, from the base station, control signaling activating a first DMRS configuration and a second DMRS configuration. The UE receives an indication for the UE to use a first transmission mode of a set of transmission modes to communicate with multiple TRPs of the base station. The UE selects at least one of the first DMRS configuration or the second DMRS configuration based on the indicated first transmission mode and a pre-defined logical association. The UE then receives DMRS signals from the TRPs of the base station, according to the selected at least one of the first DMRS configuration or the second DMRS configuration.

Abstract: A first wireless device may receive, from a second wireless device, a transmission associated with an MLC scheme. The MLC scheme may include a plurality of bits with at least one first bit corresponding to a first level of the plurality of bits and at least one second bit corresponding to a second level of the plurality of bits. The at least one first bit may be coded with a first level of complexity, but the at least one second bit may be coded with either the first level of complexity or a second level of complexity, where the first level of complexity may be a higher level of complexity than the second level of complexity. The first wireless device may decode the at least one first bit and the at least one second bit using a decoder having a corresponding level of complexity.

Abstract: Methods, systems, and devices for wireless communications are described that support a single carrier multi-level coding (MLC) amplitude phase shift keying (APSK) modulated waveform. For example, a user equipment (UE) capable to communicate using MLC APSK modulated waveforms may transmit a channel state information (CSI) report, including a recommendation for a waveform configuration, to a base station. The base station may receive the CSI report and may transmit a configuration message to the UE, which may configure the UE with a set of waveform parameters associated with MLC APSK modulation. The UE may receive the configuration message and may communicate with the base station using MLC APSK modulated waveforms and based on the set of waveform parameters, which may reduce phase noise and provide lower peak average power ratio (PAPR) signaling.

Abstract: Methods, systems, and devices for wireless communications employing multi-level coding with set partitioning on transmitting side and multi-level sequential decoding on the receiving side for latency minimization are described. In some systems, a transmitting device may transmit a code block group (CBG) to a receiving device including a first set of code blocks associated with a first decoding level and a second set of code blocks associated with a second decoding level. The receiving device may unsuccessfully decode one or more code blocks of the first set or the second set of code blocks and transmit a feedback message to the transmitting device. The transmitting device may determine that the data to be communicated via the CBG is latency-sensitive data and, as such, determine to retransmit both the first set and the second set of code blocks to the receiving device in response to receiving the feedback message.

Abstract: The base station may transmit to the UE, a first part and a second part of a PDSCH. The UE may decode the second part of the PDSCH. The first part of the PDSCH may be associated with a higher MCS than the second part of the PDSCH. The UE may estimate at least one of an ICI or a CPE associated with the PDSCH based on the decoding of the second part of the PDSCH. The UE may decode the first part of the PDSCH based on the decoding of the second part of the PDSCH. Decoding the first part of the PDSCH based on the decoding of the second part of the PDSCH may include correcting for the at least one of the ICI or the CPE associated with the PDSCH.

Abstract: The apparatus may be a UE configured to transmit, to a base station, an indication of a UE capability associated with a contiguous FD pilot; receive, from the base station, an indication of an allocation of one or more frequency sub-bands for a reception of one or more contiguous FD pilots; and receive, from the base station, the one or more contiguous FD pilots via the one or more frequency sub-bands. The apparatus may be a configured to receive, from a UE, an indication of a UE capability associated with a contiguous FD pilot; select one or more frequency sub-bands for a transmission of a contiguous FD pilot; transmit, to the UE, an indication of an allocation of the one or more frequency sub-bands for the transmission of the contiguous FD pilot; and transmit, to the UE, the contiguous FD pilot via the one or more frequency sub-bands.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit a request, for an uplink transmission or a downlink transmission, for data aided phase tracking reference signals (PT-RSs); and communicate the uplink transmission or the downlink transmission based at least in part on the request. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications are described. The following relates more specifically to hierarchical hybrid automatic repeat request (HARM) for multi-level coding with multi-level sequential demodulation and decoding and code block grouping per decoding level. A user equipment (UE) may receive, during a first time period, a transmission from a base station including a first and second code block group (CBG) with codeblocks associated with a first and second decoding level. The UE may fail to decode the first CBG, may not decode the second CBG, may store post processing samples for the second CBG, and may transmit a feedback message to the base station. The base station may retransmit the first CBG and new data on the second CBG in a second time period. The UE may decode the first CBG and use the post processing samples to decode the second CBG from the first time period.