Coordinated radio resource allocation in LTE femtocell cluster considering transport limitations

In this paper, we study the coordinated QoE-based resource allocation problem for downlink direction in a LTE femtocell cluster, considering the transport network limitation. We first formulate the problem as a convex optimization problem, which maximizes the aggregated QoE of all users and solve it using Lagrangian relaxation method. This approach provides an ideal resource allocation solution but it is not practical, because the allocated bandwidth in the model is assumed to be a real value, while in practice, only an integer amount of Physical Resource Blocks (PRBs) can be assigned to a user. However, it is considered as a benchmark for our new developed algorithms. Afterwards, we propose efficient heuristics, which can be applied in real LTE systems due to their low complexity. The performance of our algorithms is investigated and evaluated by simulations. The simulations show that the coordinated resource allocation scheme considering transport limitation results in a better average QoE compared the scheme that does not take into account the transport network capacity. Furthermore, our proposed heuristics are very close to the theoretical optimal bound.