Transmit Antenna Selection for Partially Precoded MIMO Systems

A novel antenna selection scheme is introduced in conjunction with a partial linear preceding technique for downlink and point-to-point multiple input multiple output (MIMO) systems. The proposed technique outperforms conventional channel inversion (CI) linear preceding by utilizing part of the existing inter-channel interference (ICI) between the MIMO sub-channels. It applies partial sub-channel orthogonalization in contrast to the full decorrelation of the channels attained by conventional CI. This yields an increased signal to interference-plus-noise ratio (SINR) to the multi-antenna receiver, without investing additional transmitted signal power at the multi-antenna transmitter. This benefits performance and throughput in a variety of transmission scenarios. However, the focus of this paper is on transmit antenna selection where a customized selection criterion is introduced that enhances the residue-interference optimization. Comparative simulations to conventional schemes are presented to illustrate the superiority of the proposed technique.