Fair Computation Efficiency for OFDMA-Based Multiaccess Edge Computing Systems

This letter investigates the joint optimization of task offloading and resource allocation for OFDMA-based multi-access edge computing systems. This joint optimization aims at maximizing the minimum computation efficiency, which is a ratio between the task data size to energy consumption, of all users to ensure fairness via adjusting transmit power, computation capacity and sub-channel allocations under the concrete delay, data size and energy consumption requirements. The formulated minimum computation efficiency maximization problem is a non-convex mixed-integer problem. To solve this problem, an iterative algorithm is proposed by alternatively solving the continuous sub-problem and the discrete sub-problem. For the continuous sub-problem about joint transmit power and computation capacity, a low-complexity bisection method is proposed to obtain the optimal solution by solving a series of feasibility problems. Then, the dual method is adopted to solve the discrete sub-problem about sub-channel association. Moreover, we acquire the closed-form optimal solution at each iteration. Simulation results verify that the proposed algorithm is superior over baseline schemes in terms of minimum computation efficiency.