A robust and low complexity adaptive algorithm for MIMO eigenmode transmission system under practical conditions

Adaptive MIMO eigenmode transmission system is a promising candidate for future high data rate wireless systems. However under practical conditions when channel state information (CSI) is imperfect, the eigenbeams lose their orthogonality and inter-eigenmode interference occurs. No work so far has attempted to consider the effects of inter-eigenmode interference on the adaptive signaling algorithm which is essential in ensuring a practical and robust adaptive system. Thus in this paper, we propose an adaptive algorithm that account for CSI imperfections explicitly. Our results showed that the proposed algorithm is robust and superior to conventional schemes under practical operating conditions. Furthermore, a low complexity look-up table-based computation method is also devised.