Abstract: Aiming at the low precision of the traditional carrier frequency synchronization method,a new frequency estimation method was proposed,using the traditional method to get primary frequency estimation before demodulation and using the decoding information to estimate and compensate the rudimental frequency.Simulation results show the proposed method can effectively control the fluctuation of the rudimental frequency which was brought by the traditional method，decrease the influence on system performance,get better decoding performance,reduce the demodulation threshold and lead to more efficient use of system power while not occupy more frequency band.

Key words: Frequency synchronism, Frequency estimation, Decoding information, Satellite communication