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

Abstract

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.

1 . A method for synchronizing time and frequency for return link satellite diversity in a satellite communication system, the method comprising
 Coordinate transformation in timing and frequency domain for the second return path with respect to the first path based on the timing and frequency information of a known position, e.g., the beam center;   providing a first stage timing and frequency estimation for the second path from UT to satellite by using the known information of the first path, plus the respective delay and Doppler difference of the two paths at a reference position, e.g., the beam center; and   providing a second stage timing and/or frequency estimation for the second path from UT to satellite by using the RACH via the second path provided that RACH searching window at the second path is shifted based on the first stage estimation.