Optimal Subcarrier and Power Allocation in OFDMA Mesh Networks

This paper proposes a radio resource allocation algorithm for wireless mesh networks using the orthogonal frequency-division multiple access (OFDMA) technology. We first define the utility function representing user satisfaction in terms of fairness and system throughput. Then, we formulate the optimization problem in which the total system utility is maximized subject to the constraints on the total transmission power, the subcarrier allocation to links, and the amount of data transmitted through a link. A distributed algorithm, which finds a solution to the optimization problem using the Lagrangian relaxation method and the subgradient method, is proposed. The proposed algorithm decides the transmission rates of wireless links, controls data flows to users; and allocates subcarriers to nodes in an optimal and distributive way. We show the performance and accuracy of the proposed algorithm by using simulation.