Abstract: A method for frequency and time synchronization with respect to a satellite, the method including: calculating a frequency offset ({circumflex over (f)}B,e) due to an instability of a satellite oscillator from a beacon signal (fB,TXN); determining a Satellite Motion Doppler Correction for Ephemeris (SMDCe) of a satellite motion based on ephemeris data for the satellite; computing a Satellite Reference Drift Correction for Ephemeris (SRDCe) based on the frequency offset, the beacon signal and the SMDCe; setting a loopback TX frequency based on the SMDCe and the SRDCe; and transmitting a loopback TX signal to the satellite at the loopback TX frequency.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for dynamic communication parameter selection. In some implementations, a system determines a number of resource blocks to use for one or more communications between a terminal and a gateway in a satellite communication network. The system determines a characteristic of a wireless channel used for communication, and selects a table that specifies transmission parameters to use for different combinations of numbers of resource blocks and wireless channel characteristics. The system determines transmission parameters based on an entry, retrieved from the identified table, that corresponds to the determined number of resource blocks and the determined characteristic of the wireless channel.

Abstract: A method for frequency and time synchronization with respect to a satellite, the method including: calculating a frequency offset ({circumflex over (f)}B,e) due to an instability of a satellite oscillator from a beacon signal (fB,TXN); determining a Satellite Motion Doppler Correction for Ephemeris (SMDCe) of a satellite motion based on ephemeris data for the satellite; computing a Satellite Reference Drift Correction for Ephemeris (SRDCe) based on the frequency offset, the beacon signal and the SMDCe; setting a loopback TX frequency based on the SMDCe and the SRDCe; and transmitting a loopback TX signal to the satellite at the loopback TX frequency.

Abstract: A loopback receiver to synchronize timing and frequency with a loopback signal relayed to the loopback receiver, the loopback receiver including: an Rx signal representing the loopback signal received at the loopback receiver; and a common Fast Fourier Transform (FFT) to estimate, during an acquisition mode and a tracking mode, an estimated timing offset and an estimated frequency offset of the Rx signal compared to the loopback signal, wherein the loopback signal includes a burst including a GOLD Pseudo Noise (PN) sequence having a good circular correlation and the GOLD PN sequence has cross-correlations within a set. Some embodiments may eliminate a bias of the estimated timing offset and the estimated frequency offset with double linearization.