On the Optimal Radius to Deploy Antennas in Multi-user Distributed Antenna System with Circular Antenna Layout

In this paper, the uplink of a multi-user distributed antenna system (DAS) with antennas deployed on a circle is investigated. The optimal radius to deploy antennas is studied with the target of sum capacity maximization. Adopting random matrix theory, a good approximation of the per-user sum capacity is derived. We also present a numerical method to calculate the unknown parameters in the approximation. Consequently, as the sum capacity is maximized, we find out the optimal radius of the circle on which the distributed antennas are deployed.