A Novel Single-/Multi-Layer Adaptive Scheme for Eigen Based Beamforming in TD-LTE Downlink

Abstract-Single and Multi-layer adaptive eigen based beamforming (EBB) has been proved to be a promising method to achieve the tradeoff between diversity and spatial multiplexing. But the CQI in multi-layer mode is calculated according to the CQI in single-layer mode. Lack of accurate multi-layer CQI will induce performance loss when implementing layer adaptation at eNodeB. In this paper, aiming to reduce the complexity of the UEs, we deduce a low complexity eigen value calculation algorithm. In order to considering the effects of interference among different layers, virtual equalization (VE) algorithm is proposed. On the basis of these, a novel single- / multi-layer adaptive scheme for EBB is presented. Finally, the performance of the proposed scheme is studied using semi-dynamic system level simulator.