This paper investigates the dynamic resource allocation (RA) problem in cooperative OFDMA systems, to maximize the average utility of all mobile stations (MSs) under different services. We propose a dynamic optimization framework for RA by considering three dynamic situations: time-varying fading channel, MSs states change, and relay stations (RSs) states change. Moreover, a dynamic RA algorithm based on discrete particle swarm optimization (DPSO) is proposed. The correlation between the adjacent frames is exploited to improve the performance of the dynamic RA algorithm. Simulation results show that the proposed dynamic algorithm achieves the better performance at linear complexity compared to the existing algorithms under different dynamic environments, while guaranteeing the fairness to a proper level.Index Terms-Cooperative communication, dynamic optimization, discrete particle swarm optimization, orthogonal frequency division multiple access (OFDMA), relay, resource allocation, utility function.
0018-9545 (c)