Block-Echelonization Algorithm for Multi-User MIMO Systems

In this paper, we present a new transmission technique for the downlink of a multiuser multiple-input multiple- output (MIMO) system. Recently, the block-diagonalization (BD) algorithm has been proposed for the multiuser MIMO downlink where each user has multiple antennas. The key idea of the BD scheme is to eliminate all multiuser interference by transmitting each user's data along the nullspace of the other users' channel matrix. However, the BD algorithm based on the zero- interference condition is not a proper choice when the interference is known at the transmitter noncausally. In this paper, we propose a block-echelonization (BE) algorithm for utilizing the noncausally known interference at the transmitter. The sum rate analysis and simulation results show the effectiveness of the proposed multiuser scheme.