Adaptive Bit-Interleaved Coded Modulation in MIMO Systems Using Outdated CSI

In this paper, following an analysis on the effect of channel state information (CSI) feedback delay over the eigenmode transmission MIMO system, we incorporated a bit-interleaved coded modulation (BICM) technique into the previously proposed adaptive modulation multiple-input multiple-output (MIMO) system to combat the CSI imperfection. Under a perfect CSI assumption, the optimum adaptation policy for the adaptive BICM MIMO system was obtained and both analytical and simulation results were presented showing the robustness of this system to the CSI feedback delay. Based on that, a modified adaptation algorithm was proposed, which further improved the BER performance by trading off the achieved spectral efficiency in an adaptive way.