Interference Coordination in Heterogeneous Small-Cell Networks: A Coalition Formation Game Approach

Heterogeneous small-cell networks have been identified as key technological components in accomplishing objectives of the fifth generation wireless communication system, in which the key point is the hyper dense deployment of small-cells. However, the interference among dense small-cells exacerbates in hyper dense deployment coupled with incessant use of multimedia services. In this paper, a network-side self-organized coalition formation approach for intra-tier interference mitigation primarily through neighborhood cooperation is proposed. By forming disjoint coalitions, small-cell access points (SAPs) are able to mitigate the interference within a coalition and thus improve their achievable data rates. The cooperative behavior among the neighborhood SAPs is formulated as a coalition formation game in partition form with non-transferable utility. Instead of fully reversible and irreversible methods used in prior studies, a merge and split based algorithm with partial reversibility rule which can obtain a final stable partition in the recursive core is proposed. The proposed algorithm converges to a final stable partition in a finite number of steps and works efficiently for both co-channel and orthogonal radio resource allocation modes. Simulation results have verified that the proposed algorithm can significantly improve the individual SAP throughput for both modes when compared with the conventional and the non-cooperative schemes.