Countermeasurement against Frequency Offset in Orthogonal Frequency DivisionMultiplexing Communication Systems

摘要

Inter-Carrier Interference (ICI) is one of the main problems in OrthogonalFrequency Division Multiplexing (OFDM) radio communication systems operating over time variant radio channels. This report will give a solution to this problem. First, the mechanism of ICI caused by frequency offsets is theoretically analyzed, and a new concept called Subcarrier Frequency Offset response (SFO response) is established. Then, a theoretical expression of Carrier to Interference Ratio (CIR) is derived, validated by simulations. In addition, a novel ICI self-cancellation scheme is proposed to reduce the adverse effect of frequency offsets. Both theoretical and simulation results show that by using the proposed ICI cancellation method, CIR of OFDM systems obtain more than 15 dB improvement.