Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may precode a physical sidelink control channel (PSCCH) communication using a first delay-Doppler precoder. The UE may precode a physical sidelink shared channel (PSSCH) communication using one or more second delay-Doppler precoders. The UE may transmit the PSCCH communication and the PSSCH communication in a slot after precoding the PSCCH communication and the PSSCH communication. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may precode a physical sidelink control channel (PSCCH) communication using a first delay-Doppler precoder. The UE may precode a physical sidelink shared channel (PSSCH) communication using one or more second delay-Doppler precoders. The UE may transmit the PSCCH communication and the PSSCH communication in a slot after precoding the PSCCH communication and the PSSCH communication. Numerous other aspects are described.

The embodiments of the present disclosure disclose a method for determining a parameter of a reference signal, a method for transmitting a parameter of a reference signal, a terminal device and a base station. The determination method includes: obtaining a parameter of a first type of reference signal by a first signaling; and determining a parameter of a second type of reference signal according to the obtained parameter of the first type of reference signal, and the first type of reference signal and/or the second type of reference signal include at least one of: reference signal for data demodulation, reference signal for phase noise compensation, reference signal for Doppler shift compensation, or extended reference signal for data demodulation.

The embodiments of the present disclosure disclose a method for determining a parameter of a reference signal, a method for transmitting a parameter of a reference signal, a terminal device and a base station. The determination method includes: obtaining a parameter of a first type of reference signal by a first signaling; and determining a parameter of a second type of reference signal according to the obtained parameter of the first type of reference signal, and the first type of reference signal and/or the second type of reference signal include at least one of: reference signal for data demodulation, reference signal for phase noise compensation, reference signal for Doppler shift compensation, or extended reference signal for data demodulation.

Methods, systems, and devices for wireless communication are described to support reducing a time domain selectivity of a downlink channel with multiple signal paths. A base station may spatially precode multiple channel state information reference signals (CSI-RSs) and transmit the spatially precoded CSI-RSs to a user equipment (UE), where at least one spatially precoded CSI-RS may correspond to each signal path. Based on the spatially precoded CSI-RSs, the UE may determine a mean or average Doppler shift for each signal path. The UE may transmit, to the base station, signaling indicative of the respective average Doppler shifts for each signal path. Based on the indication of the Doppler shifts, the base station may spatially and temporally precode one or more downlink transmissions to the UE, which may reduce the time domain selectivity of the downlink channel.

Methods, systems, and devices for wireless communication are described to support reducing a time domain selectivity of a downlink channel with multiple signal paths. A base station may spatially precode multiple channel state information reference signals (CSI-RSs) and transmit the spatially precoded CSI-RSs to a user equipment (UE), where at least one spatially precoded CSI-RS may correspond to each signal path. Based on the spatially precoded CSI-RSs, the UE may determine a mean or average Doppler shift for each signal path. The UE may transmit, to the base station, signaling indicative of the respective average Doppler shifts for each signal path. Based on the indication of the Doppler shifts, the base station may spatially and temporally precode one or more downlink transmissions to the UE, which may reduce the time domain selectivity of the downlink channel.

A method, performed by a first network node. The method is for handling Doppler shift pre-compensation. The first network node sends a first indication towards a first wireless device. The first indication indicates a start of a training phase. The first network node obtains, based on the sent first indication, a set of information from the first wireless device. The set of information indicates: i) a Doppler shift experienced by the first wireless device while moving along a pre-defined trajectory to which a static set of radio network nodes provide coverage, and ii) a set of features characterizing how the first wireless device experienced the Doppler shift. The first network node also initiates determining, using machine-learning, and based on the received set of information, a predictive model of Doppler shift pre-compensation. The training phase is of the predictive model.

A method, performed by a first network node. The method is for handling Doppler shift pre-compensation. The first network node sends a first indication towards a first wireless device. The first indication indicates a start of a training phase. The first network node obtains, based on the sent first indication, a set of information from the first wireless device. The set of information indicates: i) a Doppler shift experienced by the first wireless device while moving along a pre-defined trajectory to which a static set of radio network nodes provide coverage, and ii) a set of features characterizing how the first wireless device experienced the Doppler shift. The first network node also initiates determining, using machine-learning, and based on the received set of information, a predictive model of Doppler shift pre-compensation. The training phase is of the predictive model.

Some aspects of this disclosure relate to apparatuses and methods for implementing mechanisms for a network to use Doppler shift pre-compensation values for communicating Tracking Reference Signal (TRS) to a user equipment (UE) and for implementing mechanisms for triggering the UE to measure the Doppler shift pre-compensated TRS. Some aspects of this disclosure relate to a base station including a processor that determines a Doppler shift pre-compensation value associated with the UE in response to determining that the UE is moving with a speed greater than a threshold. The processor further generates an aperiodic Tracking Reference Signal (AP-TRS) or a semi persistent TRS (SP-TRS) for the UE. The AP-TRS or the SP-TRS is decoupled from a periodic TRS (P-TRS). The processor further transmits the AP-TRS or the SP-TRS to the UE. The AP-TRS or the SP-TRS can be used for time and frequency synchronization.

Some aspects of this disclosure relate to apparatuses and methods for implementing mechanisms for a network to use Doppler shift pre-compensation values for communicating Tracking Reference Signal (TRS) to a user equipment (UE) and for implementing mechanisms for triggering the UE to measure the Doppler shift pre-compensated TRS. Some aspects of this disclosure relate to a base station including a processor that determines a Doppler shift pre-compensation value associated with the UE in response to determining that the UE is moving with a speed greater than a threshold. The processor further generates an aperiodic Tracking Reference Signal (AP-TRS) or a semi persistent TRS (SP-TRS) for the UE. The AP-TRS or the SP-TRS is decoupled from a periodic TRS (P-TRS). The processor further transmits the AP-TRS or the SP-TRS to the UE. The AP-TRS or the SP-TRS can be used for time and frequency synchronization.