Conditions for Multi-Antenna Selection to be Optimal Given Channel Amplitude Information

Abstract — Transmitter designs based on partial channel state information (CSI) have become increasingly attractive in multiantenna wireless communication systems. To capture partial CSI statistics at the transmitter, we rely on a channel amplitude information (CAI) model, based on which we aim for maximizing the random channel’s average mutual information. Due to the high computational complexity required for such optimal transmissions, we resort to reduced complexity practical schemes and derive necessary and sufficient conditions for these alternatives to achieve maximal average mutual information. Index Terms — Antenna selection, channel amplitude information, multi-input single-output, Nakagami fading. most wireless systems, the fading channel amplitudes are best modeled as Nakagami distributed [1], [9], while the channel phases are generally treated as independent and uniforml