OFDM with multiple antennas has been considered in the future wireless communication systems. The challenge in the detection of a space-time signal is to design a low-complexity detector, which can remove interference resulted from channel variations and approach the interference-free bound. In this book, we employ an iterative receiver with a decoder metric, so that the bias effect in the iterations is considerably reduced, which is critical for the performance of the iterative algorithm. A new algorithm is proposed for intercarrier interference cancellation in high mobility scenarios. Furthermore, a simplified method is developed to reduce the computation complexity in the frequency- domain equalizer. In time-variant scenarios, we investigate a pilot-assisted channel estimation method under the assumption that the channel can be approximated by a linear model. The estimated channel will be used to update the frequency-domain equalizer and parallel interference canceler (PIC) in the iterative MIMO-OFDM receiver. It is shown that the proposed equalization algorithm with estimated channel state information can mitigate the effect of ICI effectively.