Time-domain method for tracking dispersive channels in MIMO OFDM systems

In this paper we address the problem of channel estimation for multiple-input multiple-output OFDM systems for mobile users. A channel tracking and equalization method stemming from Kalman filtering is proposed for time-frequency selective channels. Tracking of the MIMO channel matrix is performed in the time-domain and equalization in the frequency domain. The computational complexity is significantly reduced by applying the matrix inversion lemma. Simulation results are presented using a realistic channel model in typical urban scenarios.