Optimization Formulation of Packet Scheduling Problem in LTE Uplink

Abstract

In order to reduce the peak-to-average power ratio property, single-carrier frequency-division multiple access (SC-FDMA) has been selected as the uplink access scheme in the Long Term Evolution (LTE) system. Aiming to derive the maximum performance of the LTE uplink in terms of both average cell throughput and cell-edge user throughput, the optimization formulation of packet scheduling problem in LTE uplink is proposed in this paper. The optimization formulation defines the packet scheduling problem as a transform of the knapsack problem and utilizes the integer linear programming (ILP) method to provide the feasible optimum resource allocation based on the combination of allocable resources with various constraints in LTE uplink. Moreover, to reduce the complexity of the ILP, a limitation on the valid combination of allocable resources is also considered. Simulation results show that the feasible optimum solution derived by the proposed optimization formulation, has a significant improvement of up to 40% and 263.8% over the heuristic proportional fairness packet scheduling in terms of the average cell throughput and cell-edge user throughput, respectively. The feasible optimum solution derived by the proposed optimization formation is useful for evaluating various heuristic resource allocation algorithms.