Antenna Selection and Power Control for Limited Feedback MIMO Systems
While antenna selection has been shown to be effective in improving bit error rate (BER) performance in multiple-input-multiple-output (MIMO) systems, further performance gain can be obtained by transmitting only when the channel gains are sufficiently high and by using power control to compensate for channel variations. Truncated channel inversion is an adaptive power control scheme that compensates for fading above a certain cutoff fade depth: below the cutoff level the transmission is stopped. In this paper, we propose a novel truncated channel inversion power control based antenna selection scheme to improve the BER performance of spatial multiplexing (SM) systems with linear receivers. Power control based optimal and sub-optimal antenna selection criteria are proposed to dynamically select the number of active transmit antennas and the mapping of data substreams to transmit antennas. Simulations show that, in flat Rayleigh fading channels, the proposed power control based antenna selection scheme significantly outperforms the existing schemes in the literature.