Methods, systems, and devices for wireless communications are described. Some wireless communications systems may support non-terrestrial network (NTN) signaling between both terrestrial and non-terrestrial devices. A user equipment (UE) supporting such NTN signaling may receive a downlink message indicating a first configuration for a first transmission reception point corresponding to a first cell of the NTN, and a second configuration for a second transmission reception point corresponding to a second cell of the NTN. The UE may then perform one or more synchronization measurements to synchronize uplink communications with the first transmission reception point and the second transmission reception point and in order to perform multi-transmission reception point communications in the NTN. The UE may then transmit one or more uplink messages to the first transmission reception point, to the second transmission reception point, or both, in accordance with the one or more synchronization measurements.

A base station for communication with a terminal station having a plurality of terminal station antennas. The base station has a plurality of directional antennas, each of the plurality of directional antennas in communication with satellites in view. The base station also has a processing device (e.g., eNodeB) to transmit each of the multiple base-station antenna signals via each of the plurality of directional antennas to satellites and/or the beams of the same satellite seen by the terminal station for retransmission to the plurality of terminal station antennas.

A base station for communication with a terminal station having a plurality of terminal station antennas. The base station has a plurality of directional antennas, each of the plurality of directional antennas in communication with satellites in view. The base station also has a processing device (e.g., eNodeB) to transmit each of the multiple base-station antenna signals via each of the plurality of directional antennas to satellites and/or the beams of the same satellite seen by the terminal station for retransmission to the plurality of terminal station antennas.

Various solutions for time and frequency in non-terrestrial network (NTN) communications are proposed. An apparatus implemented in a user equipment (UE) obtains a center frequency and a reference time of a non-terrestrial network. The apparatus further obtains a feeder link delay of a feeder link between a network node and a satellite, and a service link delay drift rate of a service link between the apparatus and the satellite. Then, the apparatus performs an uplink frequency pre-compensation through calculating an uplink transmit frequency according to the center frequency, the reference time, the feeder link delay, and the service link delay drift rate.

Various solutions for time and frequency in non-terrestrial network (NTN) communications are proposed. An apparatus implemented in a user equipment (UE) obtains a center frequency and a reference time of a non-terrestrial network. The apparatus further obtains a feeder link delay of a feeder link between a network node and a satellite, and a service link delay drift rate of a service link between the apparatus and the satellite. Then, the apparatus performs an uplink frequency pre-compensation through calculating an uplink transmit frequency according to the center frequency, the reference time, the feeder link delay, and the service link delay drift rate.

A set of stators of a linear induction motor are mounted on a track. A three-phase current is provided to each of the stators, such that a traveling magnetic field (TMF) is created by the stators along the length of the track. The traveling magnetic field includes a magnetic flux corresponding to a stator excitation modulated with a message signal. A rotor includes a series of conductor plates. As the traveling magnetic field passes through the conductor plates, a current is induced in the plates by induction. Such current then generates an opposing magnetic field causing the plates and the vehicle to be propelled. Each phase may first be modulated with a message signal, before being provided to the stator. The current at the rotor is then demodulated to realize the message signal. A doppler shift due to the speed of the rotor relative to the stator is corrected.

A set of stators of a linear induction motor are mounted on a track. A three-phase current is provided to each of the stators, such that a traveling magnetic field (TMF) is created by the stators along the length of the track. The traveling magnetic field includes a magnetic flux corresponding to a stator excitation modulated with a message signal. A rotor includes a series of conductor plates. As the traveling magnetic field passes through the conductor plates, a current is induced in the plates by induction. Such current then generates an opposing magnetic field causing the plates and the vehicle to be propelled. Each phase may first be modulated with a message signal, before being provided to the stator. The current at the rotor is then demodulated to realize the message signal. A doppler shift due to the speed of the rotor relative to the stator is corrected.

Systems and methods disclosed herein provide techniques for reducing quantization errors and side lobe levels in phased array antennas. The states of a quantized phase shifter of a phased array antenna may be dithered to achieve a time-averaged value that reduces quantization errors. By rapidly switching between the different states of the quantized phase shifter, a time-average value close to a desired phase state may be achieved with a low resolution phase shifter.

Systems and methods disclosed herein provide techniques for reducing quantization errors and side lobe levels in phased array antennas. The states of a quantized phase shifter of a phased array antenna may be dithered to achieve a time-averaged value that reduces quantization errors. By rapidly switching between the different states of the quantized phase shifter, a time-average value close to a desired phase state may be achieved with a low resolution phase shifter.

A method of reducing peak to average power ratio of uplink transmission includes, assigning a slice of transmission resource to uplink transmission from a user equipment, where all resource elements in the slice have a same Doppler value, mapping data to the slice, performing orthogonal time frequency space transformation to generate time-frequency domain data and processing the time-frequency domain data for transmission.