Future mobile satellite communications systems will provide services to fast vehicles. Thus, the signal received by the user terminals may experience a wide frequency shift away from the assigned frequency that is caused by the Doppler shift and insufficient precision of the Oscillator. This paper presents a new auto-frequency control (AFC) configuration that is capable of removing a large amount of frequency offset (about ${pm}$0.6 fs, where fs means symbol rate of signal). The operational principle of the AFC is described, and its BER performance and initial acquisition time are evaluated via computer simulation.