Radio resource allocation based on dynamic user division in OFDMA cellular relay networks

In this letter, a radio resource allocation scheme based on dynamic user division is proposed to improve the spectral efficiency of OFDMA cellular relay network. For each subchannel, the user selects the relay with the best channel quality and becomes a candidate of the selected relay. The base station (BS) only transmits the user data to the corresponding relay that the user selected on each subchannel, which avoids the user communicating with the relays on bad subchannels. As a result, all user data could be transmitted high efficiently and the overall cellular throughput would be improved. Lastly, a low complexity iterative algorithm is introduced to solve the resource allocation optimization problem, which can improve the allocation efficiency while ensuring load balance among the BS and relays. Simulation results show that the proposed scheme improves throughput and fairness at the same time, therefore, higher spectrum efficiency is obtained.