An intercarrier interference mitigation technique with SSC and ASF in OFDM systems

Frequency offsets in regular OFDM communication systems distort the orthogonality between sub-carriers, which results in inter-carrier interference (ICI). In order to combat the impact of ICI on OFDM systems, an ICI mitigation technique by jointing symbol shift cancellation (SSC) and adjacent sub-channel filter (ASF) is proposed in this paper. At first, the symbol shift cancellation method is used to cancel the impact of ICI on the far sub-carriers, and then the adjacent sub-channel filter method is used to cancel the impact of ICI on the adjacent sub-carriers. By analyzing the distribution of the adjacent inter-carrier interference, a pilot-symbol scheme is proposed to improve the accuracy of channel estimation and simplify the adjacent interference filter method. The proposed algorithm can achieve trade-off between the bandwidth efficiency and the complexity of ICI cancellation method. Simulation results show that the technique proposed in this paper can effectively improve BER (Bit Error Rate) performance of the OFDM system.