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

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 for such a DAS, 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 revealed for all possible values of the radius of the circle on which antennas are placed. We then use this rate-power relationship to find the optimal radius. With this optimal radius, the circular layout DAS (CL-DAS) is proved to offer a significant gain compared with a traditional colocated antenna system (CAS). Simulation results are provided, which demonstrate the validity of our analysis.