QoS aware relay selection and subcarrier allocation in cooperative OFDMA systems

Most existing works on resource allocation in cooperative OFDMA systems have focused on homogeneous users with same service and demand. In this letter, we investigate relay selection and subcarrier allocation in a cooperative OFDMA system with considerations of QoS guarantees and service support. By introducing QoS price, this combinatorial problem with exponential complexity is converted into a convex one, and a dual based QoS-aware schedule (QAS) algorithm is proposed to tackle the problem. Simulation results reveal that our proposed algorithm significantly outperforms previous works in terms of both services support and QoS satisfaction.