Multi-Connectivity Enabled User Association

This paper focuses on the problem of multi-connectivity enabled downlink user association to maximize the overall throughput in small cell networks, which is an NP-Hard problem. We formulate the problem of user association as a linear and integer optimization problem. Furthermore, we propose a many-to-two variation of hospitals/residents matching algorithm as a heuristic solution to the problem. In this variation, users propose to small cells and the preference lists are constructed based on the distance between users and small cells. Simulation results show that our proposed algorithm achieves higher throughput rates compared to greedy and similar throughput rates compared to mathematical iterative solutions on the majority of deployment scenarios. On the other hand, we also show that the mathematical iterative methods provide better solutions that serve a greater number of users than our proposed solution when there is not enough number of small cells to provide multi-connectivity to at least half of the users in the system.