On Sum Rate of Multi-User Distributed Antenna System with Circular Antenna Layout

In this paper, we investigate the uplink of a power- controlled multi-user distributed antenna system (DAS) with antennas deployed on a circle. Applying results from random matrix theory, we prove that the per-user sum rate and the total transmit power both converge as user number and antenna number go to infinity with a constant ratio. The relationship between the asymptotic per-user sum rate and the asymptotic total transmit power is established. We then deal with a typical path loss exponent of 4, present the rate-power relationship in a closed form and find the optimal circle radius for antenna deployment. Simulation results are also provided to demonstrate the validity of our analysis.