Joint Decoupled Multiple-Association and Resource Allocation in Full-Duplex Heterogeneous Cellular Networks: A Four-Sided Matching Game

We study the joint user association and resource allocation problem in both uplink (UL) and downlink (DL) for full-duplex heterogeneous cellular networks (HCNs), wherein base stations (BSs) are densely deployed with reusable subchannels and highly variable transmit powers. To reap the benefits of BS densification, decoupled multiple-association (DMA) is considered, which enables each user equipment (UE) to associate with multiple BSs for UL and DL in a decoupled manner. Furthermore, in order to provide the best service, appropriate holistic subchannel and power allocation are jointly studied and an optimization problem is formulated. However, it is challenging to solve the joint problem due to its combinatorial nature. To this end, we formulate a novel distributed four-sided matching game in which the UEs, BSs, subchannels, and power levels are ranked based on designed preference metrics for optimal matching. To obtain the solution, a low-complexity algorithm is developed. The convergence of the algorithm to a stable matching is proved and the worst-case complexity is analyzed. Numerical results are presented to demonstrate the performance of the proposed scheme in terms of the UEs’ sum-rate in UL and DL, respectively. The superiority of DMA is also investigated by comparisons.