A method includes: determining, by a communications device, information about a target beam; determining a target monitoring occasion based on the information about the target beam and a mapping relationship between information about a beam and a monitoring occasion, where the target monitoring occasion is in a system information window, and the system information window is used for OSI; and monitoring downlink control information in the target monitoring occasion. This application is applicable to a process of information transmission between a network device and the communications device.

Methods and apparatus for obtaining a frequency offset corresponding to a Doppler shift of transmission and/or reception frequencies between a wireless device and a network node. In one embodiment a method is performed by a wireless device for operating in a non-terrestrial network, NTN, the NTN having at least one network node and a communication satellite, wherein the at least one network node is one of a terrestrial base station and a satellite base station or satellite gateway, the method includes obtaining a frequency offset corresponding to a Doppler shift of transmission and/or reception frequencies between the wireless device and the network node and applying the frequency offset to an uplink transmission to the network node.

A device includes a wireless interface configured for wirelessly transmitting a signal to a receiver; and a precoder unit configured for obtaining a first data signal to be transmitted and a second data signal to be transmitted; and for performing a first multipath-precoding of the first data signal according to a first set of paths between the device and the receiver to obtain a first precoded signal; and for performing a second multipath-precoding of the second data signal according to a second set of paths between the device and the receiver to obtain and a second precoded signal; wherein the precoder unit is configured for generating the first precoded signal and the second precoded signal such that the second precoded signal is delayed with respect to the first precoded signal at the receiver. The device is configured for transmitting the first precoded signal and the second precoded signal.

Various embodiments provide a data communication method. Under the method, a transmit end maps each code block group CBG in N CBGs to each layer in a corresponding layer group based on a correspondence between the N CBGs and N layer groups. Each layer group includes at least one layer, and N is a positive integer. The transmit end then sends data to a receive end. T transport block corresponding to the data includes the N CBGs. In this way, a mapping relationship between a CBG and a layer group is established by grouping layers, so as to improve data reception quality, through interference cancellation, for transmission among different layer groups, and ensure adaptivity to a CBG-based retransmission feedback, thereby optimizing transmission performance of an entire communications system.

Some implementations of the disclosure are directed to a satellite and cellular terminal, comprising: an indoor unit; and an outdoor unit comprising a satellite antenna and an outdoor Radio configured to communicatively couple to the indoor unit, the outdoor Radio comprising: an outdoor cellular antenna configured to communicate over a cellular communications network by transmitting signals generated using at least a cellular modem; and a feed horn configured to communicatively couple to the satellite antenna, wherein the satellite antenna is configured to communicate over a satellite communications network by transmitting signals over an inroute and receiving signals over an outroute.

The described technology is generally directed towards adaptively changing which transmission scheme a user equipment is to use based on a Doppler metric (e.g. Doppler frequency) as evaluated against a threshold Doppler value. A network instructs a user equipment to use a Rank-1 precoder cycling transmission scheme if the Doppler metric of user equipment is above a threshold value, or to use a closed loop MIMO transmission scheme if the user equipment has a Doppler metric below the threshold value. The network can instruct the user equipment via a suitable message, or by switching off TPMI and notifying the user equipment thereof.

A terminal computer includes a processor and a memory. The memory stores instructions executable by the processor to determine an initial power back-off value for establishing a communication link to a satellite as a function of a distance of a location of a satellite terminal antenna within a satellite beam footprint from a specified reference point within the satellite beam footprint, and to initiate communication with the satellite based on the determined initial power back-off value.

A method and apparatus for non-terrestrial network beam switching is provided. A non-terrestrial network base station includes a transmitter configured to transmit downlink data to user equipment and a receiver configured to receive uplink data from the user equipment. A channel bandwidth of the non-terrestrial network base station is divided into a plurality of bandwidth parts respectively corresponding to a plurality of geographic areas, and each bandwidth part is respectively associated with a satellite beam. When the user equipment is located in a first geographic area, the transmitter transmits the downlink data to the user equipment over a corresponding first bandwidth part. After the user equipment transitions from the first geographic area to a second geographic area, the transmitter transmits the downlink data to the user equipment over a corresponding second bandwidth part of the plurality of bandwidth parts.

A method for the transmission to a non-geostationary satellite of data, each device storing data, carried out by each device, includes performing successive Doppler shift estimations including receiving, by the device, a signal from the satellite comprising at least one elevation emission criterion, performing a Doppler shift estimation based on the frequency of the received signal; estimating a Doppler rate of frequency change to obtain a position of the device relative to the position of the satellite, defining a transmission window during which the position of the device relative to position of the satellite verifies the elevation emission criterion, defining a transmission time included in the transmission window and defined randomly, emitting, at the transmission time, a signal including data stored by the device and the position of the device relative to the position of the satellite.

Provided are methods and apparatuses for performing a random access of a terminal in a wireless communication system. A method, performed by a terminal, of performing a random access, according to an embodiment, includes receiving preamble configuration information from a base station, obtaining a RACH (random access channel) preamble scaled in length in proportion to a difference between an expected minimum distance and an expected maximum distance to the base station from opposed edges of a cell served by the base station, based on the preamble configuration information and transmitting the obtained RACH preamble to the base station to access a NTN (non-terrestrial network).