According to one or more of the embodiments herein, systems and techniques are provided for accurately determining a round trip time (RTT) to a satellite. In particular, a method according to one embodiment herein may comprise: receiving, at a device, a reference signal with a stable phase; measuring, by the device, a phase delta over time between the reference signal and an internal signal of an internal oscillator of the device; transmitting, by the device at a transmission time, a ranging signal toward a particular satellite; receiving, by the device at a reception time, a return of the ranging signal from the particular satellite; and determining, by the device, a round trip time (RTT) of the ranging signal that accounts for a phase drift of the internal oscillator between the transmission time and the reception time according to the measured phase delta over time.

A method transmits data via radio between a node and a base station with bidirectional radio transmission-based operation. The base station has a communication module with a first frequency transmitter. The node has a communication module with a first frequency transmitter and a second frequency transmitter with a frequency lower than the first frequency transmitter. The communication module of the node is intended to transmit data in the uplink to the communication module of the base station by virtue of a radio telegram being split into two data packets transmitted successively with a temporal spacing. The communication module of the base station transmits data in the downlink to the communication module of the node by virtue of a radio telegram being split into two data packets transmitted successively with a temporal spacing. The transmission time and/or the carrier frequency of at least one of the data packets is corrected.

The present application discloses a clock offset determination method, a clock offset processing method, a device, and a system, used to enable a base station to monitor reference signals, PRS and C-PRS, of a neighboring base station, so as to achieve time synchronization and frequency synchronization between base stations, and to resolve the issue in which a time offset caused by a frequency offset between the base stations results in the degradation of system positioning performance, thereby improving the positioning performance of the system. The clock offset determination method provided in the present application comprises: measuring a carrier-phase positioning reference signal (C-PRS) used to position a carrier phase and transmitted by a transmitter end of a positioning reference signal, so as to obtain a phase measurement value; and determining, on the basis of the phase measurement value, a clock offset between a receiver end and the transmitter end of the positioning reference signal.

A wireless communication system for a moving vehicle, and a method of operation of a wireless communication system for a moving vehicle, are described. The wireless communication system comprises an antenna system configured to receive a received signal from a further antenna system and to transmit a transmitted signal to the further antenna system, communication control circuitry to control operation of the antenna system, and analysis circuitry. The analysis circuitry is configured to obtain at least one item of information from the received signal, and perform a Doppler adjustment process to determine, based on the at least one item of information, an adjusted transmitted frequency (f.sub.t) to be used for transmission of the transmitted signal from the antenna system, such that an observed frequency of the transmitted signal at the further antenna system is a predetermined uplink frequency (f.sub.UL).

A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

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.

A method of estimating a clock frequency offset in a mobile device relative to a clock frequency of a controller within a UWB network comprises (a) determining, for each of a plurality of anchors, an anchor clock frequency offset relative to the controller clock frequency, (b) broadcasting an anchor data packet from each anchor, the anchor data packet including the respective anchor clock frequency offset, (c) receiving at least one anchor data packet at the mobile device, (d) estimating a mobile device clock frequency offset relative to the anchor clock frequency of the anchor from which the at least one anchor data packet was received, and (e) estimating the clock frequency offset in the mobile device based on the estimated mobile device clock frequency offset and the anchor clock frequency offset included in the at least one received anchor data packet. Furthermore, a TDoA-based localization method and a TDoA-based localization system are described.

In at least one embodiment, a method for measuring a distance between a first communications device including a first local oscillator and a second communications device including a second local oscillator includes unwrapping N phase values to generate N unwrapped phase values. N is an integer greater than one. Each of the N phase values indicate an instantaneous phase of a received signal. The method includes averaging the N unwrapped phase values to generate an average phase value. The method includes wrapping the average phase value to generate a final phase measurement of the first local oscillator with respect to the second local oscillator.

The present disclosure provides a communication method, including: receiving a Doppler parameter; and determining a time compensation amount for a signal based on the Doppler parameter. When the method is performed by a terminal device, the terminal device can receive the Doppler parameter from a satellite or a satellite measurement and control center. When the method is performed by a satellite, the satellite can receive the Doppler parameter from a satellite measurement and control center. Therefore, the apparatus performing the method does not need to calculate the Doppler parameter locally, thereby reducing the burden on the apparatus.

A method and apparatus for synchronizing the oscillators onboard satellites of a same network, while minimizing relativistic effects. The method consists of identifying a reference signal having minimal Doppler frequency shifting; adjusting the frequency of an ovenized oscillator to the minimally shifted reference signal, and repeating the process for all satellites of a satellite train having a similar orbital path. Subsequently, the clocks on board the satellites of a same train can be set to a same time, by relaying a clock synchronization protocol between the satellites. The method includes a number of error measurement techniques allowing to further compensate for relativistic effects and make further corrections over time.