Interference Aware CoMP for Macrocell-Based Heterogeneous Ultra Dense Cellular Networks

This paper concerns a heterogeneous ultra dense network (HUDN) with regularly deployed macrocells. Aiming to combat both cross-tier and co-tier inter-cell interference (ICI), this paper proposes a user-centric and adaptive interference aware coordinated multipoint transmission (IA-CoMP) scheme, which takes the serving or master base station (BS) and main interfering BSs decided by a signal strength threshold as cooperative nodes. The coverage performance of IA-CoMP is analyzed. The main idea is to divide MSs in HUDN into three types according to different main interference they suffer. Then the whole coverage can be obtained as the sum of the coverage of each type of MSs. A lower bound of MSs not using CoMP is derived for HUDN with IA-CoMP, which demonstrates that using IA-CoMP, unnecessary CoMP can be avoided and the overall system overhead can be reduced compared with that of the existing CoMP schemes with fixed size for all MSs. Simulations are carried out to verify the analysis and compare the coverage performance of IA-CoMP with that of cross-tier CoMP (CT-CoMP). It is shown that the proposed IA-CoMP scheme can provide a much better coverage performance especially in HUDN with higher small cell densities.