Adaptive Mode Switching Based on Statistical CSI for Downlink MIMO in Heterogeneous Network with RRH Deployment

This paper proposes an adaptive mode switching scheme for downlink MIMO in heterogeneous networks (HetNet) where low-power remote radio head (RRH) nodes are deployed within the coverage area of an existing macro network, aiming at enhancing the system sum capacity. Under the assumption that only statistical channel state information (CSI) is available at the transmitter, we derive the capacity approximations for both cooperative and non- cooperative transmission modes from the exact capacity expressions with instantaneous CSI. According to the results of the capacity analysis, simulations are presented for the proposed adaptive scheme in comparison with the exact mode switching based on Monte Carlo method using instantaneous CSI, which demonstrate its efficiency and performance gains.