Frequency-domain equalization for MIMO-OFDM over doubly selective channels

Orthogonal frequency division multiplexing (OFDM) systems may confront significant intercarrier interference (ICI) when applied in doubly selective channels. Furthermore, the insufficient cyclic prefix (CP) leads to interblock interference (IBI) which again results in ICI. These interferences cause an early error floor in conventional receivers. In this paper, we characterize the doubly selective channel using a basis expansion model (BEM) and propose a frequency-domain equalization approach to jointly combat the ICI and IBI. We also derive a low-complexity scheme for the proposed approach. Simulation results show the superior performance of the proposed equalizer.