KLT-based estimation of rapidly time-varying channels in MIMO-OFDM systems

MIMO-OFDM is a transmission method that is very sensitive to the channel time-variations arising in high mobility scenarios due to the emergence of Inter-Carrier Interference (ICI). In this paper we propose a channel estimation method using a basis expansion model that incorporates the knowledge of the channel Doppler spectrum, taking into account the statistics of the averaged coefficients of the channel. The advantage of the proposed approach is that it does not require a specific pilot subcarrier structure to estimate the ICI, and outperforms existing methods in the literature.