An Effective Inter-cell Interference Coordination Scheme for Downlink CoMP in LTE-A Systems

Coordinated multi-point (CoMP) has been adopted in 3GPP LTE-Advanced to improve the coverage of high data rates. Downlink CoMP is mainly categorized into joint transmission (JT) and coordinated beamforming (CB). Previous research shows that JT does not benefit cell average throughput. Moreover, traditional CB algorithms are based on iterative evaluation, resulting in very high computational complexity. To address these issues, in this paper, we propose an effective inter-cell interference coordination scheme for downlink CoMP, which includes two phases. Firstly, in order to improve the performance of all user equipments (UEs), cell edge UEs employ JT, while CB is adopted by both cell edge and cell center UEs. Secondly, we design linear CB precoders by maximizing a signal to leakage and noise ratio (SLNR) metric, so as to reduce processing complexity. System-level simulations validate that, in contrast to non-CoMP, the proposed scheme brings a cell average spectral efficiency (SE) gain up to 21.50% and a cell edge SE gain up to 119.2%.