Abstract: Methods, systems, and devices for wireless communications are described. In some wireless communications systems, devices (e.g., base stations, user equipment (UEs), etc.) may utilize polar coding along with hybrid automatic repeat request (HARQ) techniques. In these systems, a device may encode bits for transmission by mapping information and parity check bits to a first set of polarized bit channels of a polar code. If this transmission is not successfully received at a decoding device, the encoding device may generate a HARQ retransmission. The device may copy information bits to a second set of polarized bit channels of a second polar code containing the first polar code and may assign parity check bits to the second set of bit channels for the copied information bits. These additional parity check bits for the repeated information bits may increase transmission reliability and may support improved early termination at the decoding device.

Abstract: A device may identify that an incremental redundancy hybrid automatic repeat request (IR-HARQ) scheme is used in association with sequential transmissions of an information bit vector to or from another wireless device, where each transmission in the scheme is associated with a resource size. The device may identify a mother code length for a polar code based at least in part on an aggregate resource size associated with the sequential transmissions. The device may identify an adjusted bit index set for the polar code based at least in part on the IR-HARQ scheme. The device may transmit (or receive), for each transmission of the information bit vector, a respective subset of encoded bits generated by mapping the information bit vector to a set of polarized bit channels of the polar code in accordance with the bit index set.

Abstract: A method, apparatus, and computer-readable medium for transmitting coded messages to a receiving device including constructing a data vector including a plurality of data bits, transforming the data vector into a u-domain vector, applying a mask to the u-domain vector, encoding the masked u-domain vector with polar encoding to generate a transmission vector, and transmitting, to the receiving device, the transmission vector.

Abstract: Methods, systems, and devices for wireless communications are described that provide for channel state information (CSI) feedback for multiple discrete Fourier transform (DFT) beams on multiple transmission layers. A user equipment (UE) may report a total number of non-zero power DFT beams across all of the transmission layers. The UE may be configured with a total number of leading beams (Ktotal) across all of the transmission layers for which to provide high quantization feedback. When the total number of non-zero DFT beams across all the transmission layers exceeds the configured total number of leading beams across all the transmission layers, the UE may report high-resolution quantization feedback for Ktotal non-zero power precoding coefficients having the highest amplitude coefficients, and may report low-resolution quantization feedback for the remaining non-zero power precoding coefficients. A base station may receive the CSI feedback to determine a precoding matrix.

Abstract: Wireless communications systems and methods related to CSI feedback are provided. A user equipment (UE) receives an indication of a restricted set of frequency domain (FD) beamforming components and one or more channel state information reference signals (CSI-RSs). The UE may transmit channel state information (CSI) report indicating a plurality of precoding coefficients based on the received one or more CSI-RSs and the restricted set of FD beamforming components.

Abstract: Certain aspects of the present disclosure provide techniques for collision handling for channel state information (CSI) reporting on a physical uplink shared channel (PUSCH). A method for wireless communications by a user equipment (UE) is provided. The method generally includes receiving scheduling for at least one CSI reporting transmission and at least one uplink transmission in a same slot. The UE determines to multiplex the at least one CSI and the at least one uplink transmission in the slot or to drop the at least one CSI or the at least one uplink transmission in the slot. The UE transmits in the slot at least one of: the at least one CSI transmission or the at least one uplink transmission based on the determination.

Abstract: Certain aspects of the present disclosure provide techniques for reducing overhead for channel state information (CSI). Certain aspects provide a method for wireless communication. The method generally includes receiving a channel state information reference signal (CSI-RS), determining one or more feedback components associated with a CSI feedback type based on the CSI-RS, identifying that a payload of the one or more feedback components is to be compressed, compressing the payload, and reporting the compressed payload.

Abstract: Channel covariance feedback is disclosed for enhanced full-dimension multiple input, multiple output (eFD-MIMO) systems. Channel state information (CSI) reference signal (CSI-RS) feedback operations are implemented using spatial covariance feedback of a covariance estimate. After obtaining a set of orthogonal basis vectors, a user equipment (UE) measures the CSI-RS from a base station and determines the spatial covariance matrix from the signal. The UE may then compress the spatial covariance matrix into a lower-dimension covariance estimate matrix using the orthogonal basis vectors. The lower-dimension matrix along with element-wise quantization allows for feedback of spatial covariance for eFD-MIMO systems without excessive feedback overhead.

Abstract: Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for calculating and reporting channel state information (CSI) for time division multiplexed (TDM) based multiple transmission reception point (mTRP) transmissions.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a UE may receive multiple CSI report configurations that include at least a first CSI report configuration and a second CSI report configuration that are associated with one or more CSI reference resources; determine a dependency between the first CSI report configuration and the second CSI report configuration; and calculate at least one of a first CSI for the first CSI report configuration or a second CSI for the second CSI report configuration based at least in part on an assumption of a joint transmission using the one or more CSI reference resources, wherein the assumption is based at least in part on the determination of the dependency. report at least one of the first CSI in a first CSI report or the second CSI in a second CSI report. Numerous other aspects are provided.

Abstract: A method includes receiving, by a user equipment (UE) device, a joint transmission of channel state information (CSI) reference signals (CSI-RS) from a first transmission and reception point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network. The method further includes determining a joint rank parameter associated with the joint transmission and accessing, based on the joint rank parameter, a rank-to-port mapping codebook to determine a port index parameter. The method further includes, after determining the port index parameter, communicating, by the UE device, with one or more of the first TRP or the second TRP. Other aspects and features are also claimed and described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter device may allocate data associated with a user equipment (UE), of two or more UEs, into at least one of a first part, a second part, or a combination thereof; multiplex the first part of the data associated with the UE with a first part of data associated with one or more other UEs, of the two or more UEs, to form multiplexed data; map the multiplexed data to a first set of layers; and map the second part of the data associated with the UE and a second part of the data associated with the one or more other UEs to a second set of layers. Numerous other aspects are provided.

Abstract: The described techniques provide for the use of sub-band-specific reference signal precoding. A user equipment (UE) may apply multiple precoding matrices to a reference signal to generate a set of precoded reference signals and may transmit the precoded reference signals over respective sub-bands within a given reference signal resource set. In some cases, the UE may transmit a different set of precoded reference signals in each of multiple reference signal resource sets. Upon receiving the precoded reference signals, a base station may perform wideband channel estimation for each sub-band in the given reference signal resource set. The base station may compute an average spectral efficiency for each reference signal resource set and may transmit a report to the UE. The report may include one or more communication parameters for future communications between the UE and base station.

Abstract: Methods, systems, and devices for wireless communications are described. An encoding device may encode a set of source symbols using one or more raptor codes to generate a first set of encoded symbols and may transmit the first set of encoded symbols to a decoding device. The decoding device may successfully recover a source symbol of the set of source symbols from the first set of encoded symbols and may transmit an indication of the source symbol to the encoding device. The encoding device may encode one or more source symbols of the set of source symbols using the one or more raptor codes to generate a second set of encoded symbols based on receiving the indication of the source symbol and may transmit the second set of encoded symbols to the decoding device.

Abstract: Apparatus, methods, and computer-readable media for facilitating CSI feedback in multiple-TRP communication are disclosed herein. An example method of wireless communication by a UE includes receiving, from a base station, a report configuration message triggering a channel state feedback procedure, the UE and the base station operating in a multiple transmission and reception point (multiple-TRP) communication mode, the report configuration message requesting a multiple-TRP transmission value including at least one of a quantity of layer indicator (LI) values and a strongest TRP indicator (STI) value. The example method also includes generating channel state information (CSI) information based on the receiving of the report configuration message, the CSI information including the multiple-TRP transmission value. The example method also includes transmitting, to the base station, a report including the generated CSI information.

Abstract: Wireless communications systems and methods related to multi-transmission-reception point (multi-TRP) precoding matrix indication (PMI) operations are provided. A user equipment (UE) receives a configuration indicating a precoder size parameter for a plurality of transmission-reception points (TRPs). The UE receives, from a first TRP of the plurality of TRPs, a first reference signal. The UE receives, from a second TRP of the plurality of TRPs, a second reference signal, the second TRP being different from first TRP. The UE transmits, to the first TRP or the second TRP, a channel state information (CSI) report including a first feedback component based on the first reference signal and a second feedback component based on the second reference signal, where a combined payload size of the first feedback component and the second feedback component is based on the precoder size parameter.

Abstract: Certain aspects of the present disclosure provide techniques for using subband precoding for uplink transmissions. In some cases, a UE may transmit sounding reference signals (SRS) to a network entity, receive information indicating at least one of a set of one or more frequency domain (FD) bases and linear combination coefficients, determined based on the SRS transmission, determine subband precoding based at least in part on linear combinations of the FD bases based on the linear combination coefficients, and transmit a physical uplink shared channel (PUSCH) with the subband precoding.

Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may perform channel state information (CSI) measurements on one or more reference signal transmissions received from a base station. Based on the CSI measurements, the UE may generate a CSI report, and the UE may transmit the CSI report to the base station. In some cases, the generated CSI report may include a first portion and a second portion. The first portion may indicate whether the second portion of the CSI report includes full-band CSI feedback or partial-band CSI feedback. The second portion may provide the CSI feedback for one or more identified sub-bands. In some cases, the second portion may include a sub-band index indicating the identified sub-bands. Additionally or alternatively, the second portion may include a bitmap indicating a correspondence between multiple CSI feedback values and multiple corresponding sub-band indexes.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit an encoded transmission via a broadcast to multiple user equipment (UE). Subsequently, the multiple UEs may transmit assistance information to the base station based on attempting to decode the broadcasted encoded transmission. If the decoding is unsuccessful for at least one UE, the base station may then transmit an additional encoded transmission via a unicast or multicast message to the UEs that were unsuccessful. Additionally, the base station may transmit configuration information for the multiple UEs to receive the encoded transmissions and to transmit the assistance information. For example, the configuration information may include portion information for how long the encoded transmission is transmitted via the broadcast, via the unicast, when to transmit the assistance information, etc. In some cases, the configuration information may be based on UE metrics of the multiple UEs.

Abstract: Certain aspects of the present disclosure provide techniques for channel state information (CSI) processing occupation determination that can be used even in multiple transmission reception point (mTRP) scenarios. A method that may be performed by a user equipment (UE) includes receiving a channel state information (CSI) reporting configuration configuring the UE with a plurality of CSI reference signal (CSI-RS) resources for channel measurement (CMRs). The method includes determining a number of occupied CSI processing units, a number of occupied active CSI resources, and/or a number of occupied active CSI-RS ports based on an actual number of CSI measurements. The method includes performing CSI measurement based on the determination.