Evaluation of Joint Transmission CoMP in C-RAN based LTE-A HetNets with large coordination areas

Coordinated Multi-Point (CoMP) transmission is considered as one of the key technology enhancements for Rel-11 LTE-A systems. CoMP transmission is realized by exchanging coordination information between a set of transmission nodes, forming a so-called CoMP cluster. The size of the CoMP cluster is typically limited, which leads to cell-edge performance issues appearing at the CoMP cluster boundaries. However, in new radio access network (RAN) architectures such as Cloud RAN (C-RAN) the effect of cell-edge user performance degradation at the CoMP cluster boundaries can be minimized by considering larger CoMP coordination areas. In this paper, we investigate the Joint Transmission (JT) CoMP performance in a C-RAN implementation of LTE-A HetNet with large CoMP cluster sizes. Some approaches to minimize the CoMP processing requirements for this case are also discussed. As a baseline for comparison, the LTE-A time-domain enhanced Inter-Cell Interference Coordination (eICIC) scheme which has no coordination boundary issues is considered.