  Orthogonal frequency-division multiplexing (OFD-M) and multi-cell
architecture are widely adopted in current high speed train (HST) systems for
providing high data rate wireless communications. In this paper, a typical
multi-antenna OFDM HST communication system with multi-cell architecture is
considered, where the inter-carrier interference (ICI) caused by high mobility
and multi-cell interference (MCI) are both taken into consideration. By
exploiting the train position information, a new position-based interference
elimination method is proposed to eliminate both the MCI and ICI for a general
basis expansion model (BEM). We show that the MCI and ICI can be completely
eliminated by the proposed method to get the ICI-free pilots at each receive
antenna. In addition, for the considered multi-cell HST system, we develop a
low-complexity compressed channel estimation method and consider the optimal
pilot pattern design. Both the proposed interference elimination method and the
optimal pilot pattern are robust to the train speed and position,as well as the
multi-cell multi-antenna system. Simulation results demonstrate the benefits
and robustness of the proposed method in the multi-cell HST system.

Signal Processing