Cell identification performance based on hierarchical synchronization channels in dense small cell environment

In order to cope with the dramatic growth in the amount of data traffic, future radio access networks may consist of a large number of small cells that are densely deployed. In this paper, we focus on the identification of densely deployed small cells based on hierarchical synchronization channels specified in the Long Term Evolution (LTE) standard. The contribution of this paper is that the cell identification performance based on hierarchical synchronization channels and the problem of cell identification in a dense deployment scenario are clarified. Simulation results show that a set of user equipment (UE) applying the LTE cell identification algorithm can identify at least one small cell even in a dense deployment scenario; however, the UE can only identify a few small cells that are close to it. Furthermore, if we assume a synchronized network, miss-identification sometimes occurs due to pilot signal interference even though the received signal power of the small cell is sufficiently high. Based on the results of cell identification, we also clarify the relationship among the cell density, cell identification interval, UE speed, and quality of the connection. Initial evaluation results show that medium or high-speed UEs should employ a short cell identification interval to avoid degradation in the connection link quality; however, such UEs may suffer from higher battery consumption due to the frequent cell identification.