Low-Complexity ICI Suppression Methods Utilizing Cyclic Prefix for OFDM Systems in High-Mobility Fading Channels

This paper focuses on a simple intercarrier interference (ICI) suppression scheme that linearly combines the inter-symbol interference (ISI)-free part of a cyclic prefix (CP) and its corresponding part in an orthogonal frequency-division multiplexing (OFDM) signal to soothe the ICI effect caused by a time-varying channel. In contrast with existing heuristic combining weights in the literature for ICI suppression, we derived three sets of optimum combining weights in different aspects. Through simulations, we show that the proposed combining weights outperform other existing heuristic combining weights. In addition, a simplified implementation is introduced to reduce the computational complexity of combining. Furthermore, the proposed methods can be incorporated with other ICI mitigation methods to further improve the system performance.