Transmit antenna selection based on outage probability for correlated MIMO multiple access channels

Two new algorithms are presented to select the number and subset of active transmit antennas among the users in a correlated multiple-input multiple-output (MIMO) multiple access channel. The algorithms are based on the outage probability of a multiuser spatial multiplexing system using independent decoding with linear and successive interference cancellation receivers at the access point. A key advantage of these algorithms is the avoidance of tracking the fading channel by using channel covariance matrices rather than instantaneous channel realizations. The first algorithm selects the active transmit antennas to minimize the total transmit power among the users given the outage probability, the data rate of each user and estimates of the channel covariance matrices. The second algorithm selects the active transmit antennas to maximize the sum rate of the multiple access channel given the outage probability, the transmit power constraint of each user and the channel covariance matrices. In comparison to a system using all available transmit antennas, both selection algorithms provide significant performance gains in correlated fading channels for linear and successive interference cancellation receivers. In addition, the algorithms exhibit gains for linear receivers in independent fading