Improving MIMO Capacity in a Line-of-Sight Environment

In this paper, the optimal form of a channel matrix is derived to maximize the MIMO capacity in a LOS environment. Antenna response functions are proposed to achieve the optimal form and suboptimal results are considered. In designing an antenna to maximize the capacity, the objective is to increase the slope of the far-field phase response without sacrificing too much antenna gain. Such a constraint has not typically been considered in antenna design and should be further explored.