A Preset Threshold Based Cross-Tier Handover Algorithm for Uplink Co-Channel Interference Mitigation in Two-Tier Femtocell Networks

This paper proposes a preset threshold based cross-tier handover algorithm for uplink co-channel interference mitigation in two-tier Femtocell netowrks. The proposed cross-tier handover algorithm introduces a preset threshold cross-tier handover policy, which takes into account both the Time-to-Stay (TTS) in the Macrocell/Femtocells and the received Signal to Interference plus Noise Ratio (SINR) at the Macrocell Base Stations/Femtocell Access Points (MBS/FAPs) in making a cross-tier handover decision for a Macrocell User Equipment (MUE) or a Femtocell User Equipment (FUE). A cross-tier handover decision is made by comparing the TTS of an MUE/FUE in the Femtocells/Macrocell and the SINR at the FAPs/MBS with a preset TTS threshold and different SINR thresholds. Numerical results show that the proposed cross-tier handover algorithm can significantly improve the network performance in terms of the outage probability, the user sum rate, and network capacity.