Various arrangements for compensating for Doppler shift on a non-terrestrial orthogonal frequency division multiplex (OFDM) network are presented. A received frequency of a downlink satellite message received from a satellite may be determined. A downlink frequency delta between an expected frequency of the downlink satellite message and the received frequency of the downlink satellite message can be calculated. An uplink frequency delta based on the calculated downlink frequency delta may be calculated. An uplink transmission frequency at which an uplink OFDM symbol is transmitted may be calculated based on the calculated uplink frequency delta.

Methods, systems, and apparatus for clock synchronization are provided. In one aspect, a clock synchronization method includes: receiving, by a terminal and from an access network device, information about N clock domains, determining, by the terminal, M clock domains that are associated with the terminal and that are in the N clock domains, and separately performing, by the terminal, clock synchronization with clock sources of the M clock domains based on information about the M clock domains. Information about a clock domain includes first time information and a clock domain number of the clock domain. The first time information includes a time of a clock source of the clock domain when the access network device sends the information about the clock domain. The clock domain number identifies the clock domain. N is an integer greater than 1, and M is an integer greater than 1.

A method for locating a clock fault includes that a network device locates a clock fault source based on whether first frequency offsets between a plurality of input clocks and a local clock exceed a frequency offset threshold, or based on whether second frequency offsets between the input clocks exceed a relative frequency offset threshold.

Disclosed is a method of operating a low power wireless receiver in which a radio is periodically operable for receive intervals with sleep intervals therebetween and comprising a sleep clock having a sleep clock accuracy. A first transmission or packet is received. Based on a start moment of the first received packet, and an expected interval between packets, a nominal start moment is determined to start the radio for a packet window until a nominal end moment, for receiving a second packet; the packet window duration is extended in dependence on an estimated drift based on the SCA to provide a widened window. A start moment of a second received packet is measured within the widened window. An actual drift is calculated, from the start moment of the second packet; and an actual start moment and an actual window duration is determined, for receiving a third packet, based on the actual drift.

The present disclosure relates to access methods and apparatuses. In one example method, a terminal device determines, based on whether a first frequency offset parameter is in a frequency offset parameter range, whether to access a first cell. If the first frequency offset parameter is in the frequency offset parameter range, a current location of the terminal device is not at an edge of the cell. Otherwise, the current location of the terminal device may be at the edge of the cell.

Various aspects provide for communicating a first set of broadcast reference signals (RSs) in a first subframe that includes a synchronization (SYNC) channel and communicating a second set of broadcast RSs in a second subframe that follows the first subframe. The second subframe may immediately follow the first subframe. A portion of the SYNC channel may include information indicating a configuration of broadcast RSs in one or more other subframes. The broadcast RSs may be configured for timing-error estimation, frequency-error estimation, and/or channel estimation. Additional and alternative aspects, embodiments, and features are also provided herein.

A method for synchronizing a first device and a second device, the first device and the second device being connectable via a wireless link. The method comprises generating (202), at the first device, a synchronization signal comprising a sequence of signals, wherein each of the signals in the sequence has a first frequency; transmitting (204) the sequence of signals from the first device to the second device; performing (206), at the second device, signal processing of the sequence of signals to determine relative phase information of each of the signals in the sequence; and synchronizing (208), based on the determined relative phase information, the first device and the second device by correcting phase offset of subsequent individual signals transmitted from the first device to the second device.

An apparatus is described, comprising circuitry to obtain base station location information for a plurality of base stations that provide a wireless network for communication with a moving vehicle, the plurality of base stations comprising a current base station and one or more other base stations, circuitry to obtain moving vehicle tracking information for the moving vehicle, circuitry to determine, based on the moving vehicle tracking information and the base station location information, transmission adjustment control information associated with each other base station, and an interface configured to transmit, for reception by the moving vehicle, the transmission adjustment control information associated with at least a selected other base station, to enable the moving vehicle to adjust a signal transmitted to the selected other base station when a handover procedure is performed to transition communication with the moving vehicle from the current base station to the selected other base station.

One example method includes that a terminal device determines first random access information associated with a first synchronization broadcast block and associated with a beam parameter of a satellite beam, where the beam parameter is used to distinguish the satellite beam. The terminal sends a preamble to a satellite based on the first random access information. The satellite receives the preamble from the terminal, and determines the first random access information. The satellite determines the first SSB and the beam parameter of the satellite beam that are associated with the first random access information.

The present disclosure relates to beam handover methods, apparatuses, and communications devices. In one example method, a terminal device receives first indication information sent by a network device, where the first indication information includes a first parameter value of a first beam, and the first parameter value is a compensation amount of a frequency offset of the first beam generated by relative motion between the terminal device and the network device. The terminal device calculates a receive frequency or a transmit frequency of the first beam based on the first parameter value.