Adaptive Smart Power Control Algorithm for LTE downlink cross-tier interference avoidance

In the deployment of heterogeneous Long Term Evolution (LTE), due to the unmanaged power range of femtocells, inter-cell interference problems cause severe degradation in network performance, particularly in Closed Subscriber Group (CSG) mode. In the paper, we proposed an effective approach termed Adaptive Smart Power Control Algorithm (ASPCA), which can be applied to cluster users in coverage hole and to tackle cross-tier interference issues by determining an appropriate serving range for femtocells without requiring neither standard changing nor complicated negotiation among cells. In simulation model, several frequency-reuse-based schemes have been investigated. As a result, we demonstrate that compared to conventional way, the ASPCA significantly improved the macrocell performance about 51.32% in average user throughput but less affected the femtocell performance around 8.63% reduction in average user throughput and caused a negligible 0.46% overall loss in average throughput. The ASPCA also provided well conditions for frequency-reuse-based schemes of Inter-Cell Interference Coordination (ICIC), such as Soft Frequency Reuse (SFR) and Fractional Frequency Reuse (FFR), which can be integrated to provide the most benefit for cellular networks.