Selection of sub-carrier bandwidth in OFDM based mobile satellite communication

In mobile satellite communication systems, Doppler shift is caused by the movement of both unified equipment and satellite, and differs from that in terrestrial mobile communication. Therefore, in OFDM based mobile satellite communication systems, the selection of sub-carrier bandwidth should be different. In this paper, the characteristic of Doppler shift in the satellite communication is analyzed, and then a formula is represented to explain the influence on the theoretical system capacity from sub-carrier bandwidth with specific Doppler shift. Using the formula, this paper gives a practicable means to select the optimal sub-carrier bandwidth, and obtains the optimal range of sub-carrier bandwidth in GEO and LEO circumstances through the simulation.