ICI reduction scheme for OFDM system with phase noise over time-varying channels

For mobile orthogonal frequency division multiplexing (OFDM) systems, time-varying channels and random phase noise introduced by the oscillator result in severe intercarrier interference (ICI), respectively, and degrade the overall OFDM system performance. However, the existing ICI reduction methods only aim at a single interference source, i.e. either time-varying channels or phase noise. Therefore, these methods are not suitable for the actual situation. In this paper, we analyze the spectral property of the transfer function composed of time-varying channels and phase noise, and propose that the transfer function can be approximated by a finite parameter complex exponential basis expansion model (CE-BEM). Then, a pilot-aided minimum mean square error estimation is adopted to estimate the CE-BEM coefficients in order to reconstruct the transfer function and reduce ICI. Finally, our simulation results show how the proposed scheme would improve the system performance in a time-varying environment with phase noise. Copyright (C) 2008 John Wiley & Sons, Ltd.