Joint User Association and Rate Control in LTE HetNets

Dense small cells along with macro cells will be a part of future cellular network architecture. User association based only on signal to interference noise ratio in such dense networks can limit the user and network throughput by associating to a heavily loaded tier of cell. We propose a joint user association and rate control scheme in which user is associated to a cell tier depending on the highest achievable data rate thus maximizing the user throughput while maintaining fairness among the users. We formulate the problem as a joint user association and rate control optimization problem but decompose the original problem and solve it using gradient method. Simulation results reveal the convergence of our proposal and proportional fairness among the users.