Eigen-direction alignment design for uplink multi-user multi-cell MIMO systems

This paper has proposed an iterative eigen-direction alignment (EDA) algorithm for an uplink multi-cell multiple-input-multiple-output (MIMO) system. With a small amount of computation cost, this algorithm has decreased both inter-cell and intra-cell interference. According to semi-orthogonal user selection (SUS) scheme which achieves more multiuser diversity and higher system capacity, the EDA-based average cell capacity maximization problem is resolved iteratively, which is based on semidefinite relaxation (SDR) algorithm. The simulation results illustrate that the proposed alternating EDA-SUS algorithm with acceptable computation has a better capacity performance than the zero-forcing (ZF)-SUS algorithm. In addition, with the increasing number of transmit antennas, the advantage of EDA-SUS algorithm becomes significantly more obvious.