Weighted Sum-Rate Maximization for Downlink OFDMA Systems

We consider the weighted sum rate maximization problem in downlink Orthogonal Frequency Division Multiple Access (OFDMA) systems. A low complexity suboptimal resource allocation algorithm is proposed for joint optimization of multiuser subcarrier assignment and power allocation. This algorithm is based on an approximated primal decomposition based method, which is inspired from exact primal decomposition techniques. The original nonconvex optimization problem is divided into two subproblems and can be solved independently. Simulations are provided to compare the performance of the proposed algorithm to exhaustive search based methods and Lagrange relaxation based suboptimal methods. Despite its reduced computational complexity, the proposed algorithm provides close to optimal performance.