Coordinate ascent based resource allocation algorithm for maximizing WSMR in downlink cellular OFDMA systems

Wang, Tao [UCL] Vandendorpe, Luc [UCL]

This paper considers the downlink of a cellular orthogonal frequency division multi-access (OFDMA) system, in which multiple base stations (BSs) are coordinated by a centralized resource allocation algorithm. We address the problem of maximizing the weighted sum of the minimal user rates (WSMR) of coordinated cells subject to a total power constraint at each BS. In particular, the solution of this problem corresponds to a resource allocation that guarantees similar rates to users in each cell. We propose a coordinate ascent based iterative algorithm which alternatively updates the power allocation by solving a successive set of convex optimization problems with geometric programming, as well as optimizes the subcarrier allocation by solving a linear program for each cell. We illustrate the effectiveness of the algorithm by numerical experiments.