Capacity of multi-antenna array systems in indoor wireless environment

Previous studies have shown that a wireless system using n transmitting and n receiving antennas can achieve a capacity n times higher than a single-antenna system in an independent Rayleigh fading environment. We explore the capacities of multiple-element antenna arrays (MEAs) in a more realistic propagation environment simulated via the WiSE ray-tracing tool. We impose an average power constraint and collect statistics of the capacity with optimal power allocation, C_wf, and the mutual information with an equal power allocation, I_eq. In addition, we present expressions for the asymptotic growth rates C_wf/n and I_eq/n as n→∞ for two cases: (a) independent fadings and (b) correlated fadings at different antennas. We find that C_wf/n and I_eq/n converge to constants C_wf* and I_eq*, respectively in case (a), and to C_wf⁰ and I_eq⁰ in case (b). We observe that C_wf⁰ and I_eq⁰ predict very closely the slopes observed for simulated channels, even for moderate n (i.e., 16)