Fair resource allocation for cooperative relay OFDMA networks

In this paper, in order to improve the efficiency of wireless resource utilization, power control and subcarrier allocation are optimized jointly in a three-node symmetric cooperation orthogonal frequency-division multiple access uplink system. Equivalent direct channel gain is introduced to simplify relay links. Transmission mode selection strategy guarantees an optimal operation mode on the subcarriers allocated to each user node. Nash bargaining solution is used for fairness. The problem is formulated to maximize the overall system rate, under each user node´s maximal power and minimal rate constraints, while considering the fairness between the two user nodes. The joint resource allocation is decomposed and solved by dynamic subcarrier allocation algorithm and adaptive power allocation algorithm. Simulation results indicate that the sum rate of the system, the rate of user node and the fairness have been improved comparing to the non-cooperative strategy.