A base station in a wireless communication system is disclosed. Each base station in the wireless communication comprises: a communication module; and a processor. When the processor attempts to transmit a synchronization signal and PBCH block (SSB) at a SSB transmission candidate position in a discovery reference signal (DRS) transmission window, and fails to transmit an SSB at a first SSB transmission candidate location in a first DRS transmission window, the processor is configured to attempt to transmit the SSB at a second SSB transmission candidate position that is later than the first SSB transmission candidate position in the first DRS transmission window. The DRS transmission window is a time interval in which the base station can transmit the SSB. The SSB transmission candidate position indicates a time point at which the base station can start SSB transmission within the DRS transmission window.

Some embodiments of the present inventive concept provide a system for maintaining clock synchronization including an ultra-wideband (UWB) transmitting system and a UWB receiving system. The high precision input clock at the transmitting system produces a high precision clock frequency. A message is sent from the transmitting system including a transmit time of the message in UWB transmitter clock units. The message is received at the UWB receiving system at an arrival time in UWB receiver clock units. A time of flight (ToF) and an oscillator offset is calculated based on the transmit time included in the message and the arrival time. A tuning register uses the calculated oscillator adjustment to adjust the low precision resonator to synchronize the low precision resonator with the high precision input clock at the UWB transmitting system.

A method for operating a user equipment (UE) comprises receiving system information including: information corresponding to location coordinates for a non-terrestrial network (NTN) gateway; information corresponding to a processing delay between the UE and a base station (BS); and information corresponding to a reference point location; determining a timing advance based on a timing difference between the reference point location and the BS; and transmitting a timing advance report based on the determined timing advance.

This disclosure describes methods and systems for estimating positions of a mobile terminals. The position of a mobile terminal may be estimated based on measured timing information of reference signals transmitted by a plurality of base stations and received by the mobile terminal as compensated by non-line-of-sight (NLOS) delay times in the reference signal propagation times. The NLOS delay times may be estimated using one or more positioning anchors. Alternatively, the NLOS delay times may be estimated by using multiple spatially separate antennas of the mobile terminal, by jointly with other mobile terminals, or by using other approximation methods. The approaches provided by this disclosure facilitate more accurate position estimates for high precision mobile positioning applications.

A system and method for random access procedures in a non-terrestrial network. In some embodiments, the method includes calculating, by a user equipment (UE), a timing advance based on location information of the UE and on an ephemeris of a non-terrestrial network node. The method may further include randomly selecting a random value from a plurality of values, and sending, at a transmission time, by the UE, to the non-terrestrial network node, a random access (RA) message, which may include a signature. The transmission time may differ from a nominal transmission time by an amount based on the random value, the nominal transmission time being based on the timing advance, or the signature may differ from a nominal signature by a cyclic shift based on the random value.

An information indication method includes receiving a first message including first information. The first information indicates location information of a first synchronization signal and physical broadcast channel block (SSB) which is usable for reduced capability (REDCAP) user equipment. The method also includes determining the first SSB based on the first information.

A wireless communication method for use in a wireless terminal is disclosed. The wireless communication method comprises determining at least one synchronization value, and transmitting, to a wireless network node, a signal based on the at least one synchronization value.

Systems, methods, and software can provide high-accuracy position estimation for mobile user equipment (UE) configured for use within a service area covered by a plurality of radio units, e.g., O-RUs, with known position including coordinates. A channel estimate can be derived for a channel between a given UE and each of a plurality of radio units based on a sounding reference signal (SRS) received from the UE and used to select a subset of the radio units. The shortest delay can be calculated for the given UE to each O-RU in the subset, forming a set of uplink-time-difference-of-arrival (UL-TDOA) measurements; position of the given UE in the service area can be estimated based on the UL-TDOA measurements. The O-RU synchronization error can be estimated for each O-RU in the subset using estimated positions of the given UE and corresponding UL-TDOA measurements.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus for wireless communication at a user equipment (UE) may receive assistance information indicating synchronization signal block (SSB) set information associated with a geographic area. The UE may perform a wireless communication action based at least in part on the SSB set information. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a differential UE-specific timing advance (TA) based at least in part on a difference between a first UE-specific TA associated with a current global navigation satellite system (GNSS) position fix and a second UE-specific TA associated with a previous GNSS position fix. The UE may transmit, to a non-terrestrial network (NTN) node, an uplink message at a time that is based at least in part on the differential UE-specific TA. Numerous other aspects are described.