Abstract: Certain aspects of the present disclosure provide techniques for precoder matrix quantization for compressed channel state information (CSI) feedback. A method for wireless communications by a user equipment (UE) (120a) includes receiving a CSI report configuration for frequency domain compressed precoder matrix feedback. The CSI report configuration configures the UE (120a) to report, for a plurality of selected beams at a plurality of time domain taps, a frequency domain compression basis vector and a plurality of linear combination coefficients associated with the frequency domain compression (805). For each of the beams, the UE (120a) groups the time domain taps into at least first and second groups. The groups each can have zero, one, or more than one time domain taps (810). The UE (120a) quantizes the corresponding linear combination coefficients and/or frequency domain compression basis vectors based on the grouping (815).

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may determine that a user equipment (UE) is to use a differential reporting mode based at least in part on a channel state information (CSI) report from the UE. The base station may transmit to the UE, signaling to cause the UE to use the differential reporting mode based at least in part on determining that the UE is to use the differential reporting mode. Numerous other aspects are provided.

Abstract: A device may generate a first set of encoded bits by mapping an information bit vector to a first set of polarized bit channels of a first polar code according to a first bit index set, the first bit index set being based on respective bit channel reliabilities of the first set of polarized bit channels. The device may transmit the first set of encoded bits to another device over a wireless channel. The device may receive an indication that a decoding of the first set of encoded bits was unsuccessful. The device may generate a second set of encoded bits by mapping a repetition of at least one bit to at least one bit channel of a second set of polarized bit channels of a second polar code according to a second bit index set. The device may transmit the second set of encoded bits to the other device.

Abstract: Aspects of the present disclosure relate to wireless communication. In some aspects, a user equipment may determine at least one of: a first number of coefficients to be included in a first set of coefficients in a transfer domain that characterize compressed channel state information (CSI) for a first layer, or a first quantization scheme to be used to interpret the first set of coefficients. The UE may determine at least one of: a second number of coefficients to be included in a second set of coefficients in the transfer domain that characterize the compressed CSI for a second layer, or a second quantization scheme to be used to interpret the second set of coefficients. The UE may transmit a report that identifies the first set of coefficients and the second set of coefficients based at least in part on the determination(s). Other aspects are provided.

Abstract: Certain aspects of the present disclosure generally relate to methods and apparatus for generating and encoding bits of CSI report. In some cases, a UE may determine a payload size for channel state information (CSI) reporting based, at least in part, on a supported rank, calculate a packet length for the CSI reporting based on the determined payload size, and encode the CSI for a selected CSI resource index (CRI), based on the payload size and the calculated packet length, to generate a coded packet.

Abstract: Certain aspects of the present disclosure provide techniques for reporting channel state information (CSI) with spatial and time domain compression. A method comprises receiving one or more signals from a second wireless communications device, determining a precoder matrix index (PMI) based on the signals, performing a channel-tap compression of the PMI and transmitting the channel-tap compressed PMI to the second wireless communications device.

Abstract: Certain aspects of the present disclosure provide techniques for reporting explicit channel state information (CSI) with spatial and time domain compression.

Abstract: Certain aspects of the present disclosure provide techniques for a basis report for compressed channel state information (CSI) feedback with a non-contiguous subband configuration. A method for wireless communication by a user equipment (UE) includes receiving a CSI report configuration configuring the UE for reporting precoding matrix information including, a plurality of selected beams, a frequency domain compression matrix for each of the beams at each of a plurality of taps in the time domain, and a subset of a plurality of linear combination coefficients associated with the frequency domain compression matrices and beams. The UE receives a configuration of non-contiguous frequency resources for CSI reporting. The UE may perform frequency domain compression of the precoding matrix information using a truncated frequency domain compression matrix or performing separate frequency domain compression of the precoding matrix information for each set of contiguous frequency resources.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may perform channel state information (CSI) measurements on one or more reference signal transmissions from a base station; determine, based at least in part on the CSI measurements, a set of non-zero linear combination complex coefficients for weighting and co-phasing for a linear combination of a plurality of frequency domain basis vectors and a plurality of spatial domain basis vectors; and transmit a CSI feedback, wherein a first part of the CSI feedback includes at least an indication of a number of the set of non-zero linear combination complex coefficients with regard to all layers of a communication link between the UE and the base station. Numerous other aspects are provided.

Abstract: Configurations and feedback schemes for compressed channel state information (CSI) feedback are provided. A User Equipment (UE) determines a constraint on a total number of transfer domain coefficients to be reported for compressed Channel State Information (CSI) feedback by the UE for a plurality of beams identified for the feedback, wherein each transfer domain coefficient is associated with amplitude information and phase information. The UE selects from a transfer domain coefficient compression matrix, based on the constraint, a set of one or more transfer domain coefficients to report for each of the beams. The UE reports information indicating a number of selected transfer domain coefficients in the set of transfer domain coefficients for each beam and a location of each transfer domain coefficient within the transfer domain coefficient compression matrix and reports at least the amplitude and phase information for the selected coefficients.

Abstract: Certain aspects of the present disclosure provide techniques for reporting beam-strength related Type-II channel state information (CSI) coefficient feedback.

Abstract: Certain aspects of the present disclosure provide techniques for a coefficients report for compressed channel state information (CSI) feedback. A method for wireless communication by a user equipment (UE) includes receiving a CSI report configuration configuring the UE for reporting precoding matrix information including, a plurality of selected beams L, a frequency domain compression matrix F for each of the L beams at each of a plurality of taps M in the time domain, and a subset of a plurality of linear combination coefficients associated with the frequency domain compression matrices and beams. The UE determines the coefficients based on a first evaluation that is, for each beam, an evaluation of the amplitude of the coefficients across the taps, and a second evaluation and a evaluation that is, for each tap, an evaluation of the amplitude of the linear combination coefficients across the beams. The UE reports the first and second evaluations.

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: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may report basis subset selection for a set of beams, where the basis vectors are used for frequency domain compression. To reduce reporting overhead, the UE may transmit two reports indicating the basis vectors. The first report may include first information for the basis vectors and is of a known payload size to both the UE and a base station, while the second report may include second information for the basis vectors and may have a payload size dependent on the first information. The base station may decode the first report and may use the decoded first information to decode the second report. Based on the first and second information, the base station may determine the reported set of basis vectors to use for frequency domain compression and may determine non-zero precoding coefficients.

Abstract: Techniques and apparatus for configuring transmission rank and/or precoder(s) to support uplink non-codebook based transmission are provided. One technique includes receiving sounding reference signal (SRS) resource(s) from a user equipment (UE), where each SRS resource is associated with one or more precoded ports. At least one of a transmission rank or a set of precoders is determined based on the SRS resource(s). An indication of at least one of the SRS resource(s) is signaled to the UE. The UE uses the indication of the at least one of the SRS resource(s) to send an uplink transmission.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, configuration information indicating that the UE is to compress a precoding matrix indicator in connection with channel state information reporting, wherein the precoding matrix indicator is to be compressed based at least in part on a quantization dependency between transmission layers or an orthogonality relationship between the transmission layers, and wherein the configuration information is associated with a type II, higher rank codebook for multiple input multiple output configuration. The UE may transmit, to a base station (BS), the compressed precoding matrix indicator to the base station based at least in part on receiving the configuration information. The UE and BS may use a communication configuration based at least in part on a precoding matrix indicator recovered from the compressed precoding matrix indicator. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure provide techniques for reporting channel state information (CSI) with spatial and time domain compression.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify, based at least in part on a codebook, a set of beams to feedback in a channel state information (CSI) feedback communication, and may identify one or more beam groups associated with the set of beams. The UE may select respective one or more transfer domain bases, from a plurality of transfer domain bases, for each beam group of the one or more beam groups, and may determine a plurality of values, for a plurality of bits, that represent beam group identification information associated with the one or more beam groups and transfer domain basis selection information associated with the respective one or more transfer domain bases. The may transmit, to a base station (BS), the plurality of bits in the CSI feedback communication. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure generally relate to techniques for encoding and decoding bits of information using cyclic redundancy check (CRC) concatenated polar encoding and decoding. The CRC concatenated polar encoding techniques may avoid transmission of dummy bits. A method generally includes obtaining the bits of information to be transmitted. The method includes performing CRC outer encoding of the bits of information using an even-weighted generator polynomial to produce CRC encoded bits. The method includes performing polar inner encoding of the CRC encoded bits to generate a codeword. The method includes discarding a first code bit at a beginning of the codeword. The shortened codeword is transmitted over a wireless medium. In another method, bit-level scrambling is performed on the CRC encoded bits before the polar encoding to avoid generating a dummy bit. In another method, only odd-weighted generator polynomials are selected to avoid generating the dummy bit.

Abstract: Certain aspects of the present disclosure provide techniques for scheduling hybrid automatic repeat request (HARQ) feedback and controlling the transmit power of the HARQ feedback. An example method generally includes generating a configuration for physical uplink control channel (PUCCH) resource sets assigned to at least one user equipment (UE), wherein each of the PUCCH resources sets comprises PUCCH resources, transmitting the configuration for the PUCCH resource sets to the at least one UE, generating an uplink control reporting indication indicating the PUCCH resources associated with downlink demodulation reference signal (DMRS) port groups, transmitting the uplink control reporting indication, to the at least one UE, for use in reporting uplink control information (UCI), and receiving at least a part of the UCI associated with at least one of the downlink DMRS port groups from the at least one UE via the PUCCH resources indicated in the uplink control reporting indication.