Active antenna selection in multiuser MIMO communications

The paper develops a dynamic antenna scheduling strategy for downlink MIMO communications, where a subset of the receive antennas at certain users is selectively disabled. The proposed method improves the signal-to-leakage-plus-noise (SLNR) ratio performance of the system and it relaxes the condition on the number of transmit-receive antennas in comparison to traditional zero-forcing and time-scheduling strategies. The largest value that the SLNR can achieve is shown to be equal to the maximum eigenvalue of a certain random matrix combination, and the probability distribution of this eigenvalue is characterized in terms of a Whittaker function. The result shows that increasing the number of antennas at some users can degrade the SLNR performance at other users. This fact is used to propose an antenna scheduling scheme that leads to improvement in terms of SINR outage probabilities.