Sum-rate maximization by bandwidth re-allocation for two users in partial frequency reuse cellular networks

In this paper we apply constrained optimization techniques to optimally allocate bandwidth and transmit power to the users in a cellular network. We utilize partial frequency reuse with one user in the full and one user in the partial frequency reuse regions as inter-cell interference mitigation technique. We show that the non-convex sum-rate maximization problem becomes convex under some simplifying assumptions. Moreover, an efficient algorithm is used to solve the problem for a fixed bandwidth allocation. Our results show that in the optimum, the full amount of power is assigned to the users. We further demonstrate by simulations that re-allocating the outer cell bandwidth to the inner user when no outer user is present, results in a significantly increased sum-rate.