Resource Allocation and Scheduling in Multi-Cell OFDMA Decode-and-Forward Relaying Networks

In this paper, we formulate a joint optimization problem for resource allocation and scheduling in multi-cell orthogonal frequency division multiple access (OFDMA) half-duplex decode-and-forward (DF) relay assisted networks. Our problem formulation takes into account multi-cell interference and heterogeneous data rate requirements. We transform the resulting non-convex and combinatorial optimization problem into a standard convex optimization problem by introducing an additional interference constraint, which constitutes a performance lower bound for the original problem. Subsequently, the transformed optimization problem is solved by using dual decomposition and a centralized iterative resource allocation algorithm with closed-form power and subcarrier allocation policies is derived maximizing the average weighted system throughput (bit/s/Hz/base station). Simulation results illustrate that our proposed algorithm approaches the maximum achievable throughput and provides substantial performance gains compared to single-cell optimization.