ZF-DFE transceiver design for time-varying MIMO channels using space-time generalized triangular decomposition

We consider the design of MIMO transceivers with zero-forcing (ZF) decision feedback detection over time-varying MIMO channels. The data vectors are grouped into spacetime blocks (ST-blocks) for the spatial and temporal precoding to take advantage of the diversity offered by time-varying channels. We extend the generalized triangular decomposition (GTD) for the case of time-varying channels by introducing the space-time GTD (ST-GTD). Based on ST-GTD and the channel prediction, we propose the space-time geometric mean decomposition (ST-GMD) based system which minimizes the arithmetic mean square error (MSE) for every ST-block. We also present the causal ST-GTD based system which does not require channel prediction. The simulations show that this system achieves the same BER performance asymptotically as the ST-GMD based system. In moderate high SNR, the proposed systems have superior BER performance over the conventional GMD-based systems.