Combined bulk and per-tone transmit antenna selection in OFDM systems

We present a modification of conventional transmit antenna selection schemes for OFDM systems by combining bulk and per-tone selection. We analyse the diversity and coding gains of the proposed approach with respect to symbol error and outage probability for uncoded systems, and show that these gains are identical to that which can be obtained by employing per-tone selection using all available antennas. This analysis leads to the surprising result that one can achieve optimal performance at high SNR relative to a per-tone selection system with M antennas by first selecting only two out of M antennas and performing per-tone selection on the chosen antennas.