Techniques for wireless communications are described. A communication device may support processing digital post distortion using additional references symbols. For example, the communication device may precode a signal including at least two reference symbols for a single-layer transmission using at least two antenna ports. At least one reference symbol of the at least two reference symbols is associated with at least one data symbol of a data stream. The communication device may estimate, based on the at least two reference symbols, a nonlinearity model of at least two power amplifiers associated with the single-layer transmission, and determine an estimate of a nonlinearity factor of the precoded signal based on the estimated nonlinearity model. As a result, the communication device may eliminate or reduce the nonlinear factor of the precoded signal based on the estimated nonlinearity model of the at least two power amplifiers and the estimated channel impulse response.

A communication device includes: a plurality of wireless communication sections, each of which is configured to wirelessly receive a signal from another communication device; and a control section configured to select a wireless communication section from which a specific reception time corresponding to an optimum parameter that is a reliability parameter indicating that the specific reception time is most appropriate for a processing target is detected, as a transmission communication section serving as a wireless communication section that transmits a signal from among the plurality of wireless communication sections, and configured to measure a distance between the transmission communication section and the other communication device on the basis of the specific reception time detected from a correlation computation result obtained from signals transmitted/received between the other communication device and the selected transmission communication section.

A radio receiver includes a channel estimator processing circuit including: a feature extractor configured to extract one or more features from a received signal, the features including a channel correlation estimated based on a reference signal in a current slot, the estimated channel correlation indicating a rate of change of a wireless channel over time; and a Doppler spread estimator configured to estimate a Doppler spread of the wireless channel by supplying the features to one or more Doppler shift predictors trained on training data across a training signal-to-noise ratio (SNR) range and across a training Doppler shift range, each Doppler shift predictor being trained on a portion of the training data corresponding to a different portion of the training data.

Aspects of the present disclosure provide techniques for signaling PDCCH with relevant QCL relationships for CE for a UE to use to process a multi-TRP transmission sent using disjoint RBs.

Aspects of the disclosure include an apparatus at base station side in a wireless communication system for multi-user superposition transmission. The apparatus includes a superposition control unit and an indication generation unit. The superposition control unit is configured to insert, into a data stream of each user equipment in a group of user equipment comprising a plurality of user equipment, a demodulation reference signal corresponding to the data stream, and superpose demodulation reference signals corresponding to data streams of respective user equipment. The indication generation unit is configured to generate, for at least a first user equipment among the plurality of user equipment, an indication regarding a demodulation reference signal corresponding to a data stream of other user equipment among the plurality of user equipment, to assist the first user equipment in demodulating data transmitted in the multi-user superposition transmission.

This invention presents a channel emulator for testing a multi-user multiple input multiple output (MU-MIMO) wireless communication system using an over-the-air (OTA) connection between the antennas of a base station (BS) and the channel emulator. It uses pilot signals with special structures to estimate the channel matrix between the BS and the channel emulator, equalizes the channel when performing emulation of the channels between the BS and a plural of user equipment (UEs) in MU-MIMO communication.

Methods and apparatuses in a wireless communication system. A method of operating a base station (BS) includes receiving information of uplink transmissions; storing the received information; performing, based on the received information, channel parameter tracking operations to generate channel parameters, wherein the channel parameter tracking operations are configured with different configuration parameters; and performing, based on the channel parameters, a channel coefficient prediction operation to generate channel state information (CSI).

Apparatus, methods, and computer-readable media for sounding reference signals (SRSs) triggered by random access channel (RACH) message 2 for RACH message 4 physical downlink shared channel quasi co-location (QCL) are disclosed herein. A user equipment (UE) may transmit, to a base station via a transmit beam over a random access channel, a random access preamble and receive a random access response based on the random access preamble. The UE may transmit, to the base station via a plurality of transmit sub-beams, a plurality of SRS transmissions triggered by the random access response. The UE can receive, from the base station, a downlink control signal that includes an SRS resource indicator (SRI) that indicates a selected transmit sub-beam for a corresponding SRS transmission. The UE can use the SRI as QCL information for improved reception of downlink signaling with a refined receive sub-beam corresponding to the selected transmit sub-beam.

Various embodiments disclosed herein provide for an improved system for selecting and conveying modulation scheme information for an uplink transmission. A network device can determine the channel state information for an uplink transmission based on sounding reference signals received from a user equipment device, and then select a modulation scheme for the uplink transmission based on the channel state information and associated signal to noise ratio. The network device can then send an indication of the selection to the user equipment device using an index number comprising six bits that correspond to an index number in a table of modulation schemes. The table of modulation schemes can include modulation schemes that use transform precoding, as well as modulation schemes that do not use transform precoding.

A method for reporting, by a terminal, a measurement result for location determination according to an embodiment of the present disclosure comprises the steps of: determining whether a channel characteristic between the terminal and each base station included in a plurality of base stations configured for location determination of the terminal corresponds to a visible ray (line of sight: LoS); calculating a reference signal time difference (RSTD) by configuring, as a reference cell, one of the base stations, the channel characteristics of which correspond to a visible ray (LoS); and reporting a measurement result including the RSTD.