Methods and apparatuses for performing communication in a wireless communication system. A user equipment (UE) receives first satellite ephemeris information related to a first satellite and information related to a first validity duration corresponding to the first satellite from a base station; and restarts a first validity timer, based on second satellite ephemeris information related to the first satellite being received from the base station while the first validity timer having the first validity duration is running. The UE obtains a first TA for the first satellite based on the first satellite ephemeris information before the first validity timer restarts, expires, or stops after starting based on the first validity duration, and the UE obtains a second TA for the first satellite based on the second satellite ephemeris information before the first validity timer expires or stops after restarting based on a second validity duration.

A method and a user equipment (UE) for timing alignment is provided. The method comprises receiving, from a Base Station (BS), a first configuration indicating at least one of a scheduling offset, a common Timing Advance (TA), and satellite ephemeris information; receiving, from the BS, a second configuration indicating a TA offset for a TA variable; determining a UE-specific TA based on the satellite ephemeris information; determining a total TA based on at least one of the TA variable, the TA offset for the TA variable, the common TA, and the UE-specific TA; and starting, from a transmission by the UE, a time window after an additional time based on the total TA and the scheduling offset.

A method can include receiving sensor data, receiving satellite observations, determining a positioning solution (e.g., PVT solution, PVA solution, kinematic parameters, etc.) based on the sensor data and the satellite observations. A system can include a sensor, a GNSS receiver, and a processor configured to determine a positioning solution based on readings from the sensor and the GNSS receiver.

Methods and apparatuses for performing communication in a wireless communication system. A user equipment (UE) receives first satellite ephemeris information related to a first satellite and information related to a first validity duration corresponding to the first satellite from a base station; and restarts a first validity timer, based on second satellite ephemeris information related to the first satellite being received from the base station while the first validity timer having the first validity duration is running. The UE obtains a first TA for the first satellite based on the first satellite ephemeris information before the first validity timer restarts, expires, or stops after starting based on the first validity duration, and the UE obtains a second TA for the first satellite based on the second satellite ephemeris information before the first validity timer expires or stops after restarting based on a second validity duration.

This in-vehicle device is provided with: a determination information acquiring unit for acquiring determination information related to a vehicle; and a timing setting unit for setting, on the basis of the determination information, a timing for downloading satellite orbit information.

A vehicle positioning method includes obtaining satellite filtering parameters and satellite data, the satellite data comprising at least one of (i) a pseudo range observation value or (ii) a Doppler observation value indicating a Doppler effect. The method further includes determining a first parameter correction amount corresponding to the vehicle at a first time point to obtain positioning information of the vehicle at the first time point. The method further includes determining a second parameter correction amount corresponding to the vehicle at the second time point according to a constraint matrix corresponding to the motion state of the vehicle, and obtaining positioning information of the vehicle at the second time point by modifying the positioning information at the first time point using the second parameter correction amount.

A method for selecting a combination of GNSS satellites to carry out a position determination from a plurality of visible GNSS satellites in a GNSS receiver taking account of the variance of the satellite signals of the respective GNSS satellites includes: a) sorting the visible GNSS satellites using at least two different sorting algorithms according to predefined criteria catalogues which take account of the variance of the satellite signals, and determining at least two satellite presortings which determine GNSS satellites of which the satellite signals have a low variance according to the relevant predefined criteria catalogue; b) selecting a weighting function for weighting the satellite presortings ; c) creating a final satellite sorting by a weighting of the satellite presortings according to the relevant weighting function, so that a weighted final satellite sorting is produced; and d) carrying out a satellite combination selection on the basis of the final satellite sorting.

A method can include receiving sensor data, receiving satellite observations, determining a positioning solution (e.g., PVT solution, PVA solution, kinematic parameters, etc.) based on the sensor data and the satellite observations. A system can include a sensor, a GNSS receiver, and a processor configured to determine a positioning solution based on readings from the sensor and the GNSS receiver.

A method, apparatus, and system are disclosed for providing modified orbital assistance data to a mobile station to determine its location using global navigation satellite system (GNSS). The modified orbital assistance data may include predicted orbital information for the GNSS satellites combined with antenna phase center offset data for one or more GNSS satellites. The antenna phase center offset data may indicate an offset distance from the center of mass of the GNSS satellite to a position on an antenna of the respective GNSS satellite. The modified orbital assistance data may be in an earth-centered earth-fixed (ECEF) frame of reference and the antenna phase center offset data may be in a body-centered frame of reference.

Techniques for enhanced Global Navigation Satellite Systems (GNSS) position determination can include capturing an image, from a camera, of obstructions near a mobile device. Orientation information regarding the camera can is used to determine where, in the image, the horizon is situated, and which portions of the sky are blocked by the obstructions from the perspective of the mobile device. Information regarding the location of satellites in the sky is obtained, based on an estimated position of the mobile device. Obstructed satellites can then be identified by comparing the location of the satellites with the obstructed portions of the sky. In a GNSS position determination, information received from the obstructed satellites can then be disregarded or de-weighted accordingly. In some embodiments, the information regarding the blocked portions of the sky can be sent to a server and/or shared with other nearby mobile devices.