A Distributed Subcarrier and Power Allocation Algorithm for the Downlink in OFDMA Systems

The problem of resource allocation for OFDMA downlink is investigated in this paper. The problem is formulated as a rate adaptive problem, which is to maximize the system throughput while subject to total transmission power constraints. A distributed resource allocation scheme to solve this combinatorial optimization problem is presented. The problem is decomposed into a principal problem with regard to the base station and several subproblems with regard to the users. In particular, we consider regarding users as relay nodes that could send feedback information back to the base station. By solving the subproblems, each user obtains its own subcarriers and power allocation scheme. The base station could make sure all the constraints are met and the system throughput is maximized by solving the principal problem. Simulation results show that the proposed algorithm converges quickly to an approximated optimal solution in a small number of iterations.