Adaptive resource allocation in cooperative OFDM networks for throughput and fairness improvement

Cooperative communication in multi-user orthogonal frequency division multiplexing (MU-OFDM) networks is a promising solution to combat wireless channel fading and to increase system throughput. In this paper, with the instantaneous channel state information (CSI) available at base station, the optimal resource allocation strategy is considered in MU-OFDM networks, which is to maximize throughput and ensure fairness in entire network. We show that this problem is formulated as a mixed binary integer programming problem. Thus we decompose this optimization problem into four sub-optimal problems. First, the dynamic user choosing strategy is proposed. Second, a subcarrier choosing strategy is given by making use of the equivalent channel power gain. And the adaptive power allocation scheme in base station and in relay station is given at last. The simulation results show that our proposed algorithm can greatly increase throughput and ensure fairness.