Limiting behavior of receive antennae selection

In this paper we investigate the limiting behavior of receive antenna selection in single-input multiple-output (SIMO) wireless systems when the number of receive antennas gets very large. Using results on the convergence of the trimmed mean, we show that mutual information converges in distribution to the logarithm of a folded Gaussian distribution in the limit of a large number of receive antennas. The convergent distribution also shows there is channel hardening in this scenario like SIMO maximum ratio combining. For finite number of receive antennas, N, we derive the exact outage probability for SIMO with selecting the best S receive antennas. This outage probability analysis is used to study the rate of convergence of the mutual information, which reveals that the rate of convergence increases with the number of selected receive antennas in medium and high SNR regimes and decreases in the low SNR regime. We also show that the multiuser scheduling gain at low SNR is proportional to the square root of number of selected receive antennas, √S, in the limit of large number of users. These results could be useful in designing next-generation wireless systems, such as 4G, where the requirements are to increase the transmission rate by increasing the number of antennas and at the same time decreasing the complexity of the system.