MMSE-based equalization and ICI mitigation scheme for OFDM system over doubly selective channels

Inter-carrier interference (ICI) caused by time-variant multi-path channels degrades the performance of orthogonal frequency division multiplexing (OFDM) based digital terrestrial television broadcasting systems, especially for large number of sub-carriers and high speed mobile reception. In this paper, we propose an minimum mean square error (MMSE) based equalization and ICI mitigation scheme for mobile HDTV transmission. Our algorithm applies a simplified MMSE equalizer before the calculation of ICI compensation term for ICI mitigation, while remains acceptable computational complexity for realization. Numerical simulation results show that the MMSE-based algorithm outperforms the zero-forcing (ZF) equalizer, especially for large Doppler frequency offsets.