Low complexity ICI cancellation for OFDM systems in doubly-selective fading channels

Abstract

In orthogonal frequency division multiplexing (OFDM) systems, rapid variations of doubly-selective fading channels lead to a loss of subcarrier orthogonality, resulting in inter-carrier interference (ICI) and system performance degradation. Although some methods have been proposed to suppress ICI, they are computationally complex or at the price of sacrificing spectral efficiency. In this paper, we provide an ICI analysis in both time- and frequency-domains while existing literatures analyze the ICI effects mainly in frequency domain. Based on this analysis, we propose a novel ICI mitigation scheme whose complexity is linear in the OFDM symbol length. The method uses iterative ICI cancellation in the time domain. We provide theoretical analysis and simulation results to show that the proposed method can effectively mitigate ICI caused by channel variations with a low computation complexity and high spectral efficiency.