Efficient MIMO Order and Transmit Antenna Subset Selection in Correlated Channels

In this work we propose a transmit antenna selection (AS) strategy which adaptively controls the considered maximum number of RF modules (MIMO order), which are then selectively mapped to appropriate antenna subsets. The selection of number of RF modules depends on the channel correlation and receive SNR. Therefore we studied the behaviour of correlated MIMO channels under various correlation and SNR scenarios. Subsequently we derived by capacity evaluation a lookup table (LUT) to select the optimal MIMO order setup. LUT presents the correspondence between the number of RF modules and particular channel conditions. Furthermore a search reduction criterion along with different sub optimal transmit antenna subset selection procedures have been proposed. It has been observed that under certain channel conditions a smaller number of RF modules maximizes the mutual information while maintaining the BER requirements.