Method and system for providing timing and frequency synchronization for satellite diversity

摘要

An approach facilitates synchronization by providing: (i) a method to analyze the two-satellite synchronization problem in time-frequency domain; and (ii) a two-stage estimation method to accomplish timing and frequency synchronization. The embodiment facilitates satellite diversity. The embodiment applies to a system involving two or more geosynchronous satellites.

主权项

1. A method comprising:
determining, by a processor of a communications device, a timing and a frequency for a data transmission associated with a communications terminal over a channel within a beam of a first satellite of a communications network, wherein the determinations of the timing and frequency for the data transmission over the channel of the first satellite are based on a first position within the beam of the first satellite; determining, by the processor of the communications device, a timing and a frequency for the data transmission associated with the communications terminal over a channel within a beam of a second satellite of the communications network, wherein the determinations of the timing and frequency for the data transmission over the channel of the second satellite are based on a second position within the beam of the second satellite; determining a timing estimate and a frequency estimate for the data transmission over the channel of the second satellite, wherein the determinations of the timing and frequency estimates are respectively based on timing and frequency relationships between the first satellite and the second satellite; adjusting a receive window of a secondary receiver of the communications device based on the determined timing and frequency estimates for the data transmission over the channel of the second satellite; receiving the data transmission over the channel of the second satellite, wherein the data transmission is received within the receive window of the secondary receiver and reflects a received timing and a received frequency relative to the receive window of the secondary receiver; determining a secondary timing delta and a secondary frequency delta reflecting respective offsets of the received timing and received frequency relative to the receive window of the secondary receiver; and acquiring synchronization for subsequent data transmissions associated with the communications terminal over the channel of the second satellite based on the determined secondary timing and frequency deltas.