Fuzzy layered physical cell identities assignment in heterogeneous and small cell networks

Massive irregular deployments of small cells require corresponDing physical cell identities (PCIs) in heterogeneous cellular networks. The number of PCIs is restricted by the synchronisation sequence result in PCI reuse at an appropriate distance among base stations. Some methods of PCI assignment are given either globally optimal or completely preferential. Accordingly, the former cannot guarantee handover performance, and the latter may lead to low efficiency of allocations. A layered allocation algorithm based on fuzzy clustering is proposed. Simulation results show that it can improve the efficiency of the PCI assignment, while maintaining handover performance.