Distributed User Association and Femtocell Allocation in Heterogeneous Wireless Networks

Deployment of low-power low-cost small access points such as femtocell access points (FAPs) constitute an attractive solution for improving the existing macrocell access points' (MAPs) capacity, reliability, and coverage. However, FAP deployment faces challenging problems such as interference management and the lack of flexible frameworks for deploying the FAPs by the service providers (SPs). In this paper, we propose a novel solution that jointly associates the user equipment (UE) to the APs, and allocates the FAPs to the SPs such that the the total satisfaction of the UEs in an uplink OFDMA network is maximized. We model the competitive behaviors among the UEs, FAPs, and SPs as a dynamic matching game and we propose distributed algorithms to find the optimal UE association and FAP allocations. We show analytically that the matching algorithms converge to the optimal and stable outcomes after a small number of iterations. Simulations and analytical results show the proposed mechanism is arbitrarily close to the global optimal solution by setting a design parameter (step number) but has significantly reduced overhead and complexity over the centralized algorithm.