Enhanced distributed resource allocation and interference management in LTE femtocell networks

Femto cells have been integrated into 4G Long Term Evolution (LTE) cellular network architecture to efficiently address the coverage and capacity issues faced in indoors and at hotspots. Though spectral efficiency increases through frequency reuse one at Femtos, it could lead to co-tier interference and cause higher interference for cell edge User Equipments (UEs). This problem is more severe in enterprise and hotspot Femto deployments due to dense placement of Femtos. Existing co-tier interference management techniques do not solve this problem completely. Hence, in this paper, we propose a Variable Radius (VR) algorithm which dynamically increases or decreases the cell edge/non-cell edge region of Femtos and efficiently allocates the radio resources among cell edge/non-cell edge region of Femtos so that the co-tier interference between neighboring Femtos can be avoided. We implemented the proposed VR algorithm on top of Proportional Fair (PF) scheduling algorithm in NS-3 simulator. In our experiments, for 90 UEs the proposed technique (VR + PF) achieved 29% and 38% improvement in average throughput for static and mobile scenarios, respectively when compared to classic PF algorithm without any interference management.