  Heterogeneous Networks (HetNets) are introduced by the 3GPP as an emerging
technology to provide high network coverage and capacity. The HetNets are the
combination of multilayer networks such as macrocell, small cell (picocell and
femtocell) networks. In such networks, users may suffer significant cross-layer
interference. To manage the interference the 3GPP has introduced Enhanced
Inter-Cell Interference Coordination (eICIC) techniques, Almost Blank SubFrame
(ABSF) is one of the time-domain technique in the eICIC solutions. In this
thesis, we propose a dynamically optimal ABSF framework to enhance the small
cell user downlink performance while maintains the macro user downlink
performance. We also study the mechanism to help the small cell base stations
cooperate efficiently in order to reduce the mutual interference. Via numerical
results, our proposed scheme achieves a significant performance and outperforms
the existing ABSF frameworks in terms of user throughput and outage
probability.
