A New Modeling Approach for Utility-Based Resource Allocation in OFDM Networks

A new modeling approach is proposed for utility- based resource allocation in orthogonal frequency division multiplexing (OFDM) networks with heterogeneous traffic. The spectrum and power of a base station (BS) are allocated to users, in a point to multi-point manner, to maximize the users´ aggregate utility. We first model the problem of assigning sub-carriers to the users and the power allocation to the sub-carriers as a mixed integer nonlinear programming (MINLP) problem. The MINLP problem is maximizing a non-concave objective function over a non-convex feasible region that includes some integer variables. We then eliminate integer variables and propose a continuous nonlinear programming (NLP) model for the problem. The obtained model is suitable for heuristic and search algorithms. Genetic algorithm (GA) is applied to obtain the near optimal solution of the NLP model. Numerical results are presented to illustrate the convergence of the GA and utilization performance of the network.