Abstract: Certain aspects of the present disclosure provide techniques for generating and using channel state information reference signals (CSI-RS). In some aspects, a method for generating a Channel State Information-Reference Signal may include: generating a pseudo-random base sequence based on at least a time parameter of the CSI-RS; modifying the pseudo-random base sequence based on at least a frequency parameter of the CSI-RS to form a modified pseudo-random sequence; generating the CSI-RS based on the modified pseudo-random sequence; and transmitting the CSI-RS to a user equipment.

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: Aspects of the present disclosure relate to techniques for codebook subset restriction (CSR). In some cases, a user equipment (UE) receives, from a network entity, codebook subset restriction (CSR) information. The UE determines, based on the CSR information, a restricted beam set for a plurality of antenna panels, determines precoding matrix indicator (PMI) feedback for the antenna panels subject to restricted beam set, and provides the PMI feedback to the network entity.

Abstract: Methods, systems, devices, and apparatus for wireless communication are described that relate to transmission of a set of precoded reference signals, and using a physical resource group (PRG) size for the resources carrying the set of reference signals for channel estimation at a user equipment (UE). For example, a base station may apply a precoding matrix to a set of reference signals, and the reference signals may be configured on a set of resources. In such cases, the resources including these reference signals having a same precoding may be included in a PRG, and a size of the PRG may refer to a number of precoded reference signals for which the precoding is the same. Based on the received reference signals and the PRG size the UE may perform channel estimation based on the PRG size and transmit channel state information (CSI) to the base station.

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: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive or determine information identifying a mapping of one or more codewords with regard to one or more layers, wherein the one or more layers include at least one of: a first set of layers, wherein a fraction of bits associated with each layer, of the first set of layers, is for data associated with the UE, or a second set of layers, wherein all bits associated with each layer, of the second set of layers, are for data associated with the UE; and perform rate matching or decoding based at least in part on the information identifying the mapping. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may perform a first polar code encoding process on a first transmission of a hybrid automatic repeat request (HARQ) process; generate a second transmission of the HARQ process by relocating a portion of bits in less reliable positions of the first transmission to more reliable positions of the second transmission of the HARQ process, wherein the less reliable positions and the more reliable positions are evaluated based at least in part on a channel transform, wherein the channel transform is based at least in part on the first transmission, the second transmission, the first polar encoding process and a second polar encoding process associated with the second transmission; and transmit the second transmission of the HARQ process. Numerous other aspects are provided.

Abstract: Aspects of the disclosure relate to wireless communication. In some aspects, a user equipment (UE) may receive an indicator, in a physical downlink control channel (PDCCH) payload, that indicates whether the PDCCH payload includes data or downlink control information (DCI) for obtaining the data, wherein the indicator is an initial state of a cyclic redundancy check that includes a predefined sequence of bits; and obtain at least one of the data or the DCI based at least in part on the indicator. 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: Certain aspects of the present disclosure relate to methods and apparatus for channel-war polar code construction.

Abstract: Certain aspects of the present disclosure provide techniques for aperiodic channel state information (A-CSI) feedback scheduling for cross-carriers. Certain aspects provide a method for wireless communication. The method generally includes receiving on a first component carrier (CC) signaling indicating an aperiodic channel state information (CSI) report request for a plurality of CCs; determining schedules for at least CSI reference signal (CSI-RS) transmissions on the CCs based on the received signaling; monitoring CSI-RS transmissions on the CCs according to the determined schedules; and reporting CSI feedback based on CSI-RS measurements of the CSI-RS transmissions.

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: Certain aspects of the present disclosure generally relate to methods and apparatus for generating and reporting CSI.

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: Methods, systems, and devices for wireless communications are described. A transmitting device, such as a base station or a user equipment (UE), may generate a first set of encoded bits using a polar code. The transmitting device may transmit the first set of encoded bits to a receiving device, but the receiving device may unsuccessfully receive the transmission. The transmitting device may prepare a retransmission by generating a second set of encoded bits. In some cases, the transmitting device may copy information bits from the first transmission to polarized channels when generating the polar code for the retransmission. The transmitting device may copy information bits based on how the information bits were assigned for the first transmission as well as the block length. The transmitting device may copy information bits such that the retransmission is self-decodable.

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: 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: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an encoding device may determine a least reliable subset of information bits included in a set of information bits that includes a predefined active set of information bits to be encoded; may determine a codeword bit to be added to a codeword based at least in part on the least reliable subset of information bits, wherein adding the codeword bit to the codeword improves reliability of the least reliable subset of information bits; may add the codeword bit to the codeword; and may transmit the codeword. Numerous other aspects are provided.

Abstract: Some wireless communication networks may improve communication reliability and/or throughput using multiple-input, multiple-output (MIMO) schemes. MIMO operation may in turn be supported by the use of channel state information reference signals (CSI-RS), which may allow communicating devices to estimate and leverage multipath channel conditions. However, the signaling used to support such communications may consume significant resources. In accordance with the described techniques, a user equipment (UE) may identify non-zero-power beams based on received CSI-RS. The non-zero-power beams may contribute to the final precoding vector. Rather than transmitting beam coefficients relating to zero-power beams, the UE may instead indicate a presence of these zero-power beams to the base station (e.g., by indicating a number of non-zero-power beams). Such techniques may reduce overhead of the communications or otherwise benefit the system.

Abstract: Methods, systems, and devices for wireless communications are described. An encoder of a wireless device may receive a transport block (TB) for transmission and segment the transport block into a set of multiple, smaller data segments that respectively In correspond to a plurality of code blocks of the TB. The encoder may generate a code block level (CB-level) error detection code (EDC) for a subset of the data segments. The encoder may generate a transport block-level (TB-level) EDC for the TB using the data segments. Each of the code blocks (CBs) may be of the same size and may include one of the data segments. A subset of the CBs may include a data segment from the subset of the data segments and one of the CB-level EDCs. The remaining CBs that are not part of the subset may include a remaining data segments and the TB-level EDC.