A Dynamic Channel Assignment Algorithm for OFDMA Systems

In this paper, we propose a heuristic dynamic channel assignment (DCA) algorithm to achieve the tradeoff between system throughput and fairness in downlink OFDMA systems. The proposed algorithm is divided into two stages: first, a proportional fairness is taken into account with quality-of- service (QoS) guaranteed to users for the system to accommodate as many users as possible; second, the remaining subcarriers are assigned for system throughput to be maximized. Numerical results reveal that a good tradeoff between system throughput and fairness is achieved. Furthermore, as a performance measure, the probability of outage is significantly reduced when compared to the optimal water-filling algorithm.