Comparative Study between CFO and SCFO in OFDM Systems

OFDM has emerged at the beginning of the second half of last century. Its applications are diverse and extend to different wireless and optical communication systems. It is well known that OFDM is very sensitive to frequency shifts. The imperfections of the local oscillators of the transmitter and receiver affects the carrier, while the Doppler-effect affects the carrier, also the sub-carriers of the OFDM signal. This gives rise to inter-carrier interference (ICI) responsible for the degradation of system performance. In this paper we have studied OFDM in a radio mobile channel. We proposed a new model that includes the offsets generated by the Doppler-effect at different sub-carriers. We compared it with the existing model which considers only the carrier frequency offset and we calculated the error between the two mathematical models.