Intracell Handover for Interference and Handover Mitigation in OFDMA Two-Tier Macrocell-Femtocell Networks

There are two main access policies (open and closed) to Femtocell Access Points (FAPs), being closed access the customers favorite. However, closed access is the root cause of crosstier interference in cochannel deployments of two-tier networks (i.e., macrocells and femtocells). Further, the effect of this problem is remarkably serious in the downlink of outdoor users not subscribed to any femtocell. Open access has been considered as a potential solution to this problem. However, this increases signaling in the network due to the elevated number of HandOvers (HOs) that mobile users have to perform. Therefore, this paper proposes an interference avoidance technique based on the use of Intracell HandOvers (IHOs) in Orthogonal Frequency Division Multiple Access (OFDMA) femtocells. It is shown that a proper combination of IHO and power control techniques reduces the outage probability for nonsubscribers compared with that of closed and open access. In addition, the impact of several network parameters such as the femtocell penetration is also considered in the analysis.