A multi-mode space-time coded MIMO system using lattice-reduction aided detection

This paper presents a multi-mode space-time coded MIMO system with the assistance of lattice-reduction-aided MIMO detection. The proposed system switches among a number of pre-designed signaling modes, which include the spatial multiplexing (SM) and quasi orthogonal space-time block coding (QOSTBC) with different code rates. By switching among these signaling modes, the system dynamically trades off between spatial multiplexing and diversity gain according to the instantaneous channel state information. In order to further reduce the computational complexity of decoding, we also introduce the lattice-reduction (LR) technique in the proposed system. The performance advantages of the proposed multi-mode system are demonstrated via extensive computer simulations.