Inter-Carrier Interference Cancellation in OFDM via Independent Component Analysis

Inter-carrier Interference is a severe problem in OFDM systems. Frequency offset is a factor which destroys the orthogonality of subcarriers and causes Inter-carrier Interference (ICI). In the case of insufficient Cyclic Prefix (CP), delay dispersion of the channel can also lead to ICI. Time variations of the channel over an OFDM symbol duration can be considered as another factor causing ICI. In this paper the ICI mathematical formulation is derived and a blind cancellation method, which is based on Independent Component Analysis (ICA) is proposed. Practical solutions for the ICA ambiguities are also considered. The effectiveness of the method in various situations, including the mentioned ones is demonstrated via simulation.