Performance of Combined Bulk and Per-Tone Antenna Selection Precoding in Coded OFDM Systems

A simple but effective way of precoding signals in multiantenna OFDM systems using antenna subset selection (fewer RF chains than antennas) is per-tone antenna selection, which can be applied to the chosen subset. In this paper we study the performance of coded systems using this type of precoding and compare it to bulk selection and per-tone selection when all antennas are used. The diversity is the same for all three schemes but the analysis shows that the coding gain of the combined scheme is superior to the bulk selection and not much worse than per-tone selection. These conclusions are verified by simulations and show that bulk antenna selection with subsequent per-tone selection is an effective way of achieving good performance with limited cost.