A Physical Cell Identity Combinatorial Optimal Configuration Scheme Based on PCIs Grouping and Cells Clustering

Physical Cell Identity (PCI), as a significant network configuration parameter, is a key factor in the process of User Equipment (UE) accessing to the cell. There are more cells than the number of PCIs, as cell density grows in the ultra dense network, unreasonable PCI configuration will cause conflicts, confusions and Mod- $k$ conflicts (CCM) between cells. However, there is still a lack of work related to the effect of the Mod- $k$ conflict during PCI configuration. In this paper, we propose a PCI configuration scheme that can reduce the occurrence of CCM among cells by using PCIs Grouping and Cells Clustering (named as PGCC). First, a CCM graph is established based on location and handover rate among cells. Second, PCIs are divided into different groups according to Mod- $k$ conflicts, and cells are clustered by the number of groups. Then, the graph coloring algorithm is used to configure the PCI based on the grouping and clustering. Finally, the effectiveness of the scheme is verified by numerous simulation experiments. Compared to other schemes, the PGCC scheme can reduce CCM between cells.