The present disclosure provides methods and systems for improving the time synchronization of global positioning system (GPS) satellite systems and related methods of using such systems. In some aspects, the GPS satellite systems comprise a swarm of CubeSat or other small form factor satellites.

A method for performing a handover analysis is provided. The method can include obtaining base station location information for a plurality of base stations that provide a wireless network for communication with a moving vehicle, obtaining position and velocity information for the moving vehicle, and generating at least one handover metric computed from the position and velocity information and the base station location information, for use in determining a target base station to be used when performing a handover procedure to transition communication with the moving vehicle from the current base station to the target base station. This enables a variety of handover metrics to be generated that take into account the deployment of the wireless network, which can be useful in systems such as Air to Ground (ATG) systems where the moving vehicles have a relatively high velocity, and the base stations may be relatively far apart.

A method includes receiving a current velocity and a current position of a mobile node relative to a fixed node. The method also includes identifying a receive time slot for the fixed node to receive a transmission of a data packet from the mobile node and determining a propagation delay for the data packet between the mobile node and the fixed node based on the current position of the mobile node. The method includes determining a transmission time based on the receive time slot and the propagation delay and determining a Doppler shift based on the current velocity of the mobile node. The method includes determining a transmission frequency based on the Doppler shift and a clock rate correction. The method also includes transmitting the data packet to the fixed node at the determined transmission time using the determined transmission frequency compensated by the determined clock rate correction.

A method and an apparatus for carrier frequency-offset determination and a storage medium are provided. The method includes the following. A first carrier initial frequency-offset is obtained according to a pilot time interval and a pilot phase difference of a first carrier. A second carrier frequency-offset is obtained according to a carrier frequency-ratio of a second carrier to the first carrier and the first carrier initial frequency-offset. A first carrier frequency-offset is obtained according to the first carrier initial frequency-offset.

Wireless communications systems and methods related to signaling of direct current (DC) locations of user equipment devices (UEs) in a new radio (NR) network are provided. A wireless communication device receives, from a base station, at least one of a carrier aggregation (CA) configuration or a bandwidth part (BWP) configuration. The wireless communication device determines a direct current (DC) location based on at least one of the CA configuration or the BWP configuration. The wireless communication device transmits, to the base station, a report based on the determined DC location. The wireless communication device communicates, with the base station, a phase tracking reference signal (PTRS) configured based on the report.

Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may transmit a capability message indicating a parameter configuration for each phase error process of a set of phase error processes of the first UE. The first UE may transmit, to a second UE, a phase error process indicator to indicate that the first UE is using a first phase error process of the set of phase error processes to generate a sidelink transmission in accordance with the parameter configuration for the first phase error process. The second UE may monitor, via a sidelink channel, for the sidelink transmission based on frequency tracking, phase tracking, time tracking, or any combination thereof being performed in accordance with the parameter configuration for the first phase error process. The first UE may transmit, via the sidelink channel, the sidelink transmission to the second UE.

A method for communicating between a first radio frequency communications device including a first local oscillator and a second radio frequency communications device including a second local oscillator includes generating phase values based on samples of a received signal. Each of the phase values indicates an instantaneous phase of the received signal. The method includes unwrapping the phase values to generate unwrapped phase values. The method includes generating frequency offset estimates based on the unwrapped phase values. The method includes generating an average frequency offset estimate based on the unwrapped phase values. The method includes wrapping the average frequency offset estimate to generate a residual frequency offset estimate. The method includes adjusting the first local oscillator based on the residual frequency offset estimate, thereby reducing a frequency offset between the first local oscillator and the second local oscillator.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to a base station, a report that indicates a phase tracking reference signal (PTRS) density for a PTRS. The UE may receive, from the base station via a downlink shared channel, the PTRS in accordance with the PTRS density based at least in part on the report. Numerous other aspects are described.

Provided is a method for automatically calibrating wireless frequency offsets. The method includes following steps: a wireless fidelity (Wi-Fi) wireless transmission module monitors or scans a specific data packet of an access point (AP); the Wi-Fi wireless transmission module acquires a frequency offset between a central frequency of the Wi-Fi wireless transmission module and a central frequency of the AP according to the specific data packet; the Wi-Fi wireless transmission module executes frequency offset tracking according to the frequency offset to control the Wi-Fi wireless transmission module to calculate a central frequency according to a frequency offset acquired for a surrounding AP of the Wi-Fi wireless transmission module in such a way that each of the calculated central frequency and the frequency offset for the surrounding AP is in a preset standard, and adjusts the central frequency of the Wi-Fi wireless transmission module according to the calculated central frequency. Provided is also a device for automatically calibrating wireless frequency offsets.

A system and method for transmission indications are disclosed herein. In one embodiment, the system and method are configured to allocate, by a wireless communication node, a time gap for a wireless communication device to monitor a synchronization-assistance signal, wherein the time gap is periodically or aperiodically allocated along a time-domain. In an alternate embodiment, the system and method are configured to receive a synchronization-assistance signal during a time gap, wherein the time gap is periodically or aperiodically inserted along a time-domain according to a wireless communication node.