Efficient relay selection and subcarrier assignment in cooperative OFDMA systems with QoS guarantees

This paper investigates relay selection and subcarrier assignment in cooperative OFDMA systems with considerations of QoS requirements. The joint resource allocation problem is formulated as a 0-1 integer linear programming problem with the objective of maximizing the system throughput. The efficient joint optimal algorithm is proposed to tackle the problem. By using the penalty function, the complicating constraints are included in the objective function and the special model with a totally unimodular constraint coefficient matrix is constructed that could be solved rapidly as a linear programming with reduced computational complexity. Numerical results show that the proposed algorithm significantly outperforms previous works in terms of both heterogeneous services support and QoS guarantees